Cover anything electronic and spray with water. I use Adam's All-Purpose Cleaners and a soft long hair brush. Spray & let it sit for a few minutes and brush everything off. Use the "shower" on the spray hose, not the "jet" & rinse. Unless the dirt is caked on, this usually works for me. I dry it off using an air compressor or leaf blower. Once dry, I spray some Adam's In & Out spray on the plastic parts. It really works great for areas you can't get to easily with an Armor All type product and doesn't leave the surface greasy.
I'm sure other products will work, but I already had the Adam's stuff so that's what I used. Just don't use the engine de-greasers you see in auto parts store. Those can get really aggressive and leaves a noxious odor if you don't rinse everything off. Not to mention, the stuff stains your driveway.
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