When Mathews leaves the diner to go across the street and stake it out, he gets into his car. There is truck with a left directional on, indicating his turn into the diner's parking lot. There is also a larger truck behind it. When Mathews drives away, there are no trucks in the background.
When Sid knocks out Joe in the car, Joe is in the driver's seat. However , when Sid hops into the driver's seat to let the car roll down the hill towards Mathews' approaching car, Joe is now on the passenger side. Sid never moved him nor could Joe have moved himself because he was unconscious.
When Mathews runs out of the diner after discovering that Ginny fled, you can see a crew member inside of the diner.