It only really rained once during the shoot, and it did so during the filming of one of the biggest scenes. The rain was coming down so hard the paths in the woods turned into small streams, and the cast and crew quite literally ran back to the production cars carrying whatever they could under rain jackets.
The first campfire scene was five pages long and was completed in one long take. To make matters more interesting, the shot needed to be filmed at twilight, so the cast and crew had only 30 minutes to get the take.
In the original script, the car was supposed to be a Volkswagen Beetle but was changed to a 1968 Galaxie Ford due to budget costs. This change also required a change in the film's title, which was originally: "A Girl, A Boy, A Bug and a Very, Very, Very Long Road."