Had to clean a fair bit of rat droppings from my car when I got back from The Yook. There's no food but it has been very wet, so it'd be a dry refuge for them. (relatively, it leaks a lot).
Its a sub-compact though, so not really space for that thing.
I've been seen beating the bonnet (hood) of my previous car with a tree branch, a la John Cleeze, when I surprised nesting rats in the engine compartment.
I'm afraid of rats.