From the map, I'm fairly certain there would be no "campsite" or rural type setting elsewhere on this creek, to be applicable to a place she might have been left other than here. The creek/watershed begins in between backyards in residential developments and that's all it flows between, until it gets to this area where she was found that is winding past a local schoolyard/public city park. No campground or rural place to have driven a car into. If this is her, either:
1 he damaged his car here driving into the park/schoolyard itself, getting the car closer to where he was going to hide her, or
2 he damaged his car elsewhere that evening -
....such as, somewhere more rural (in the 4-4:30 window, say) he pulled off the road, tried to rape her, she resisted and ran, he hit her with his car and killed her and put her in his trunk, and he damaged his car driving in or out of that intended rape spot, after which he decided to get a shovel and hide her here by a walking trail in a park.