what to clean the underside with

[r4daytona]

Getting ready pack up the car for winter and wondering what to clean the underside with.  It's been painted gray to resemble primer and has red overspray like it should - so that's the surface I'm cleaning.  It's not horribly dirty but does have some dirt, a little bit of oil spots here and there - typical stuff.  I was thinking of using brake parts cleaner because it's great for cleaning my hands but didn't know if that might be to harsh for the painted surfaces.  Any suggestions??

Also, any tricks to get the stuck rubber from the underside behind my rear tires?  It was fun putting it there, but now I have to clean it.

[TUFCAT]

I found that charcoal lighter fluid is the best for removing melted rubber and won't hurt paint (don't ask me how I know...)    It's also great for oily residue.

[Homerr]

I'd suggest using undercoating on it.   

[hemi68charger]

Simple Green works great Tom... Paper towels and once it is all done, or maybe as your progressing, a damp sponge with warm water to wipe down the road grime. I would stray away from harsh chemicals... Sometimes good paint polishers/cleaners from Mequires works well with rubber.....

[TUFCAT]

Simple Green works great Tom... Paper towels and once it is all done, or maybe as your progressing, a damp sponge with warm water to wipe down the road grime. I would stray away from harsh chemicals... Sometimes good paint polishers/cleaners from Mequires works well with rubber.....

I agree! A safe solution product like Simple Green does the job and should be used first.  But when it gets really tough.... get out the charcoal lighter fluid.

The golden rule is to always start out with safest product no matter what you're cleaning.  My first step to clean stuff is usually dawn soap, then move into something more. I've also used compressed air instead of abrasives to get things moving and unstuck depending on the grime level.

Then if it still needs a boost I head over to the chemical closet....starting at mild, then moving onto wild.  You never want to find out how lacquer thinner reacts to vinyl.... if you don't already know.    

[bill440rt]

I haven't had to use any really strong solvents to remove road grime, maybe some standard bug/tar remover once in a while which probably isn't very far off from lighter fluid.

I usually get a bucket of a mild soap solution with hot water (car wash soap, etc). I'll wring out a washcloth with the stuff, wash/wipe off the dirt & dry with another rag. Sometimes a spray first with diluted Simple Green or a mild orange cleaner works well also. After dried off I'll then use a detail spray to finish it off & get rid of any other spots. Or a spray wax on the floor pans. I prefer rags over paper towels.
I wipe heavy grease off first with a rag before cleaning suspension parts. Once you find a system that works you'll find it doesn't really take that much time. I can clean the whole underside of the car in a little over an hour.

[r4daytona]

Thanks guys.

[John_Kunkel]

The belly of airplanes presents a similar problem and hand cleaner (without grit) works great on them....just apply, let sit and hose it off.