its his lot...so he made a complaint to the culprit
motor oil and asphalt don't go well together...oil will stain concrete but can be cleaned up but on asphalt I think it has to be washed off with soap and water. How would any oil get to the ground? If its in the lease you can be help responsible for the damage if any to the parking lot. Maybe renters insurance may cover it...it wasn done deliberately just and accident...RIGHT?
Rat Rods Rule!