When Jack decides to take a power saw and make their car into a "convertible", Pilot is seen asleep in the driver's seat on interior shots, but the car is empty in several of the exterior shots.
A URL is painted on the side of a parked trailer. It's partially blanked out in one shot but visible from another camera angle. No company would have been advertising a web site in 1994.
When 'Miranda Pandas' slide into the trash cans in front of Jack's house, you see the camera man's reflection in the car door.
When Jack decides to turn the car around and go to Seattle, a stunt double is clearly seen behind the wheel doing the U-turn.
The girl that Pilot (Jake Gyllenhaal) is chasing after is named Amy Carnes--it even says it clearly in the subtitles--but during the end credits it is misspelled as "Amy Barnes."