This is definitely non-technical but nevertheless crucial. I have noticed rat droppings appearing underneath my car right below the engine compartment. Anybody got any solutions to get rid of this bloody pest?
Do you park the car in a warm location? They love warmth, the sign of food and any strong smell.
Perhaps you could try parking the car outside for a few weeks to get rid of the problem where the temperature is much lower, but I would suggest trying to get to the root of your problem, i.e. is your garage/house/street host to rats?
Set up some rat traps around your garage or in your engine compartment at night.