Mouse nests can be a problem, but the other stuff they leave (poop and urine) absolutely MUST be removed. They're a big health hazard, and the urine is highly corrosive. Even if you have to cut coupon-sized access holes inside the cab structure and patch them later, don't leave that stuff in there!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!