When the group begins driving from Arkansas to Reno, they are seen near an exit sign for De Valls Bluff and Biscoe, Arkansas. This exit sign is on I-40 east almost halfway between Little Rock and Memphis, thus they were heading in the wrong direction for Reno.
The movie was released in late 2002. The "brand new" Chevy Suburban they make the cross country trip in is the 1992-1999 body style. Granted the Suburban was 'eaten' by the Robosaurus at the end of the show, so perhaps the producers did not want to sacrifice an expensive brand new vehicle.