That might be quite good actually, Salmonella.
Yea, so even if the bomb fails, but explodes, you have to pay. But there's one problem. What if someone new uses the system and they don't have any money, even the welcome money? Or, you have some money for it, but spend it in the space of time the car's timer is set? You could get a free explosion unless there was a system that kept track of loans and automatically took the money when you get it. If it's a new player that has used up their welcome money and will never come back, it will be free.