Many times, we have people come to us who have been in a car wreck in a parking lot. Private property is almost never going to have law enforcement generated report. That means it's really important to document the scene yourself, try and find other sources of documentation on it, and talk to an attorney early.
A lot of times we have a he said, she said, where two people are backing out of a parking lot and hit one another. Well, many times in parking lots locally, we have video surveillance, that if you talk to an attorney early enough, we can send a letter to Walmart, for example, and get a copy of that video. Then it's very clear who's at fault.
If you wait a while, that video no longer exists, and then the he said, she said may not end up in your favor. Most of the time on private property, law enforcement won't fill out a police report or an accident report. They will tell you it's a private matter on private property, and that they won't come and investigate unless there's a serious injury.