Many of the police cars got badly damaged and/or soiled during the movie-trial scrimmage, yet eight of the ten vehicles are shown to be clean and traveling just fine near the end of the episode.
When Howie parks Country Joe's car behind Seaver's truck, the truck is surrounded by brush and is square on the path. In fact, it looks parked exactly as it was the night before when Righteous shoots him in the back (with blanks). When Howie and Seaver come out 15 minutes later to find the car gone, stolen by Country Joe, the truck is clearly not at the same location;. It is in an open area, with no immediate brush around it.
When the goons' limo-driver says that the car is unable to move, the shift-lever is clearly pushed all the way up, indicating that it is in the "park" position.
After the boy is hit by the car, Colt calls in the accident as having happened at the intersection of Yucca and Gower. The location at 6201 Yucca Street is closer to Vista Del Mar Avenue than Gower Street.