So you are a tow truck driver and someone calls you to get their car repaired? Once you have the car at the tow yard, press F3 on the vehicle (works better on drivers side) and input an amount up to 1500 (remember, a repair costs 1k) and then the person will accept or deny it. If they accept, talk to the repair NPC and get the car repaired.
Note: Taking money and not repairing will result in a ban and blacklist.
Someone feel free to prettify this. It's just a quick thing I did cause its new.