Years ago there were a lot of farms around here, and they would track dirt from their property out into the streets making the rural roads dusty. A lot of farmland has been replaced with subdivisions so it's not as bad as it used to be.

Detailers and mechanics still use Hotsy pressure washers and engine degreaser on trade-ins and customer cars being serviced. Low mile new stuff with better made gaskets and tighter machining tolerances don't really leak oil like the older vehicles did. It all depends on who owned it, and where they drove it at. If you camp, hike, or fish around here like many do chances are you'll find yourself driving on miles of dirt roads to get to the good spots, which will make your engine compartment filthy if you follow behind anyone for long enough. Most vehicles get the engine compartment washed to get rid of dust buildup more than degreased these days.