I take my ramps and coveralls over to the local coin-op carwash every couple months,and get things up in the air high enough i can crawl under them and wash the hell out of the bottom side ,as i hate working on dirty vehicles,lol. I'm not really a believer in trying to keep things clean using spray on crap and a garden hose,i prefer to wash the engine/transmission/rearend etc. with high pressure soap ,then i'll even use the carwashes spray on wax after washing.Also gives me a chance to look things over for leaks while i'm under it washing it. Probably not for everybody,but i'm a touch a n a l when it comes to keeping my vehicles spotless top and bottom,lol.