Despite the fact that they are vacationing in January, and everyone has heavy coats on at the beginning of the movie, when the couples arrive at the RV park, everyone is swimming in the pool.
Just over an hour in Frank says to Roger that the oil cooler is "mashed up against the radiator, there". But there is no damage to the grill.
When the motorhome is being pursued by the white pickup truck, Peter Fonda's character throws one of the scramblers off the rear bike rack. When we see him doing this, the motorhome is driving down a narrow single track road with bushes on each side. Immediately afterwards, the view switches to the pickup, which is driving along a much wider road with a central divider.
When Frank is showing Roger the recreational vehicle bathroom, his shirt is buttoned, but when he turns around his shirt is unbuttoned and he is buttoning it.
As the couples pull into the RV park, there is a wide shot of the park with Kelly and Alice in bathing suits heading for the pool. However, the next shot is of the RV parking and the couples exiting the RV before Alice and Kelly decide to go for a swim.
When Frank is introducing Roger to the RV he says 'Stereo, four channels'. This is perfect for a pedant to jump on and claim that of course quadraphonic is four channels whereas stereo is two.
The car that flies off the bridge and explodes starts to explode before it hits the railing. Not to mention that cars don't just explode on impact.
Roger (played by Peter Fonda) rams a a red truck off a bridge during a chase scene and it explodes. In the wide shot of the truck falling, the bridge's safety railing is entirely intact.
While there are remote areas of Central Texas, even in the 1970s cities such as Odessa, Midland, Abilene and Lubbock were all far closer than Amarillo. As Texans from San Antonio, the group would have known that and traveled to one of those closer locations.
Hard to believe that Frank would keep driving during the rattlesnake scene.