A life-long fan of camping, Jeff Daniels has owned an RV for years. According to a Detroit radio interview, his RV driving lessons for the movie were quickly canceled when he arrived on location in his personal recreational vehicle.
The script originally called for a 1990s recreational vehicle, but Sonnenfeld wanted something more classic. His search yielded two 1948 "Flexible Clippers," which were used in the '40s and '50s by such companies as Greyhound and Trailways. Both were in reasonably good shape when the production acquired them. The seats were stripped away, the bodies restored and painted an eye-catching red and cream (they were originally blue and white) and outfitted like vintage motor homes. Other exterior appointments included "eyelid" shades over the headlights, a chrome ladder up the back and a wooden roof rack to complete its distinctive classic look. The second bus was completely rebuilt, including engine and drive train, with only about 60 percent of the interior restored. It was used mainly for stunt work and second unit exterior shots.
The Munro RV is a Forest River, Georgetown 359 TS. Five of them were purchased, plus a sixth which was ordered in pieces and assembled in a way that allowed hydraulic rams to raise and lower it out of the lake. Two were fitted with special suspension hydraulics to handle some of the extreme driving moments. Two of them are the ones that the Munros are seen living and driving in. The 5th was dubbed "Wild Thing" and was fully functional.