i played on my own dedicated server when these issue happens (persistence was never modified in the server files)

Sedan persistence issue:
i put all my loot on a saden and then leave it where it is to find vehicle part to repair it, after several SERVER RESTART the vehicle is gone when i come back.

Sedan self destruction:
i parked the car with level 3 gear, and go for loot, after about 10 minutes and a SERVER RESTART when i come back to the vehicle i found its completely ruined.