NOTE: This spoiler was sent in by Koalakat.

The movie starts off like it does in the trailer, with Robin Williams' character having a sweet conversation with his young daughter around her bedtime. After some cute shenanigans, Cheryl Hines' character walks in carrying a young boy and makes a comment to the effect of "great now she's more awake then when I gave her a bath". The scene concludes with Robin Williams' character saying that "no matter what happens we'll always be best friends".

Cut to several years later. Robin Williams is driving a BMW x5 with his family riding along, with the little girl played by that one girl JoJo (you know the chick that sang that song "Get out, leave, I don't want you no more" or whatever) asking him when he became such a loser. Kinda funny but sad at the same time. They are on their way to go pick up a friend of hers at her house, and apparently the girl has no idea where she lives, but remembers a fountain.

The family ends up at some corporate get-together in a backyard bbq type atmosphere, where we are introduced to Robin Williams' germaphobe boss and fellow coworkers. Apparently Williams' character works for some energy drink company, and the company is doing well. Williams suggests that the two girls make small talk with the boss, so they do. However, it ends up going horribly wrong, as the only reason the friend wanted to tag along was to accuse the big boss in person of contributing to the bad health of children nowadays, and ends her rant by throwing a large vat of green goop in his face. The next scene is of the family dropping off the friend, which she merrily thanks them for inviting her to go to the laughter of the audience. Williams makes a quick movement as if to run the girl over and Hines' character just says "Don't". Amusing.

Next we see Williams' character at the office, with the Big Boss using some of that Purell Instant Hand Sanitizer stuff every so often. He says he was considering firing Williams after what happened, but has decided instead to give him a second chance at some conference deal in Colorado. Williams reminds the big boss of his plans with his family to go to Hawaii, which the boss basically tells him to cancel if he wants to keep his job. Flash forward to the family at home, which paints a picture that the family doesn't communicate all that much, and is very much looking forward to the trip to Hawaii.

Well, the next day or so we see the girl's character sitting on the couch, and as shown in the trailer, a big RV pulls up in front of the house. Williams calls in sick to the office so he can get a head start in the RV. The family packs up their belongings, and start the adventure. A funny scene happens where at first Williams' character is having EXTREME difficulty with his seatbelt, which actually happens alot during the course of the film, then trying to drive the RV and get it turned around. He ends up crashing into a lot of stuff, but once he gets going, turns on the navigation system, which he has nicknamed Lola. The wife tells him to go one direction, while the navigation says another.  He ends up making a hard right turn to follow the navigation's directions, and all the plates and such that were stowed in the cabinets falls all over the girl in the back.

The next scene is of them coming out of a grocery store with supplies, where Williams makes a call to the RV guy whose name he cannot remember, despite the fact that it is emblazoned on the side of the RV in large letters. The RV guy tells him he must have damaged the parking brake and such when he maneuvered the RV in front of his house, and must now use chalks and a mallet to keep the RV in place. (Funny scene is shown where the RV rolls into a large train of carts)

Next we see the RV driving along, as a shopping cart dislodges itself after having created a large amount of sparks on the road. The next scene is them arriving at the first RV park, and getting settled. The boy (who is most irritatingly shown as being some wannabe gangster thug) tells Williams that the toilet is all backed up, (the previous renters didn't empty the tanks) so they have to go to a dump station and empty it themselves. The girls are uninterested and set up beach chairs in the lot. The boys go to a dump station and begin the hilarious examination of hoses and such. A family behind them decides to help them out with their dumping because it is quite obvious the boys have no clue what they are doing. A VERY funny scene happens with the pumping, and needless to say, Williams somehow ends up the victim of a tank eruption.

Now covered in waste matter, Williams looks up to see Jeff Daniels' character telling him he shouldn't trust the people he did, because they don't really know what they're doing. Daniels hoses him down and invites him to dinner with his family that night. Williams thanks him kindly, but says he is in charge of the cooking on their trip and should get started. Well cut to a scene where the family asks how much longer its going to take for the food to be ready...not soon at all. They decide to take up the offer of the other family, who turn out to be quite odd indeed.

The family ends the night with a song and dance number, which I thought was actually quite good. The main family runs away in fright, and say they are early risers so they appreciate dinner, but won't be able to see the other group again. Ever.

Well, that night we find out that Williams' character has to work on this proposal for work, so he sneaks off to the RV park's bathroom and goes into a stall to work. Well the youngest kid from the freaky family has some disorder like insomnia so he doesn’t sleep, so he’s just wandering around the RV park all night, doing whatever. (he also compliments Williams on his laptop, important later) Well, the hours go by and Williams is finally done with his report for work, but can’t get any signal in order to send it…so he gives up temporarily and snuggles up in bed with his wife, only for the alarm to go off 30 seconds later…the family rushes to get things organized so they can hurry up and leave before the freaky family makes their way over for breakfast.

So they’re on the road, and they get stuck behind a tractor thing and the daughter basically calls him a pussy cuz he won’t pass the tractor, well he goes to do it and barely makes it….so they stop at a gas station cuz their gas tank is now dangerously low. Well, Williams grabs his laptop and decides to see if he can send it from the bathroom stall of the gas station, but his son interrupts him before he can finish so he hides it behind the toilet tank of the stall. After bumping into the freaky family at the gas station, they say they will hook up with them for a picnic or something, but run away…so Williams quickly tries to get his laptop, but there was a kid in the bathroom when he was who ended up taking it. The kid hops a ride on some truck, and is gone…thus leaving Williams laptop-less.

They are shown driving off, with the gas pump thing still stuck in the tank, because of the haste in which they left. (I thought that was great because you had to notice it to find it funny) Then they get to the next RV park and there’s a funny couple of scenes where they try to get rid of a few raccoons in the RV. They end up using a stink bomb to get the raccoons out….and end up sitting in lawn chairs outside in the pouring rain…the kid goes to see if there’s a place to go inside to get out of the rain, and slips down the side of a mountain, which is now a sort of water-slide. They go in the diner looking like crap, and share a laugh. That night Williams uses his palm/blackberry thing to type up another report in the bathroom of the RV…he finishes and ends up climbing all over stuff to get it to send…which it finally does. The next morning they leave and go to an outdoor walk place where Williams pretends to have a really bad stomach problem, so the family will go without him, because his boss called him and said he wanted him to give a presentation to prospective clients.

 He gets them to go on ahead, and rushes back to the RV to change and head over to the clients’ house. He arrives and finds out that his “rival” at the company is there as well. The rival starts to give a presentation but chokes so Williams takes over and does really well. They go to leave and the boss tells him to come back the next day and sell it to the whole company or something. So Williams heads back but there’s a huge traffic jam, so he has to take an alternate route called “Devil’s Pass”….it’s called that for a reason. Scenes from the trailer are shown, where Williams somehow gets the RV stuck on a huge stalactite looking thing, and then the RV makes it over, only to go plummeting down a hill with Williams holding on to the windshield wipers for dear life. REALLY FUNNY scene.

 The RV ends up rolling over him (he doesn’t get hurt because he’s laying supine) and the family shows up to see him lying on the floor. They drive off to see some scenic view of a lake, and have a cute family bonding experience, only for the RV to go into the lake and disappear. The truth comes out that Williams was doing this for work, and the family is pissed. So Williams walks into the lake and disappears…only to come out of the lake riding one of the bikes that has been hooked up to the back of the RV for the whole trip. He takes off on the bike, to try and get to the meeting in time (to save his job).  The family starts walking, and guess who shows up….the freaky family.

 The freaky family had been shown earlier, picking up the same hitchhiker that stole the laptop.  The kid recognizes it as belonging to Williams, so they kick the hitchhiker out, and try and find the Williams family on the road, because they know they’re headed to Denver.

 Well, the Williams family, minus Williams himself obviously, is now in the freaky family’s RV, and they’re driving along. Williams is on his bike, on some mountain path, and sees the freaky family’s RV and his family with them at a gas station. So he barrels down the hill to try and catch them, and ends up coming up behind the RV, to grab onto the rear “stairs”.  He climbs on, loses his $4000 bike (funny scene where he explains the bike) and is now riding on top of the RV. He climbs to the front and pokes his head down so the RV slams to a halt, and then they all confront him.

 Then there’s a scene of apology, they make up and then find out that they’re at the conference, thanks to Jeff Daniels. He gives a good speech, and then at the end, says that the company should not go into a partnership with the creepy big boss, because he’s exactly that. Creepy. Well, they get chased off, and end up (somehow) in the old RV that’s been pulled out of the lake. They get pulled over by a cop and get out of the RV to find out that the owners of the small company had been looking for Williams because they want to hire him. (the creepy big boss fired him)

 Williams is really happy, and then the RV (because of the parking brake problem) rolls over the cop car and the business owners fancy car…..

 Roll credits