If they look that bad where you can see it, you probably get a good idea of how poorly the engine and other systems may have been maintained.
We looked at our RV offered used by a private seller a few miles from us, and were impressed by the like-new immaculate interior condition. A guy who owned a garage nearby made a passing comment that "he (the owner) takes very good care of his vehicles." Must have been true, since we never had a problem.
A real estate agent once told me she often saw high dollar houses for sale, filthy with dishes piled up, trash and bugs everywhere. Then the owners wonder why no one's interested.
