You can use just about any over the counter spray cleaner or detergent. Mainly, you just need to remove oil and debris (dirt & bugs here in Nebraska.)

What I have found is that if you wax the monokote first, cleaning is much easier and the covering will look better longer. Just use any good auto wax that does NOT include silicone. The silicone stuff will make it real difficult to perform repairs as the covering will not stick to it. I use Meguiars Cleaner Wax - paste form.

As for the actual cleaning chemical, anything that will cut the oil is fine. Windex, 409, a few drops of dish detergent in water or alcohol, etc. Some leave a residue, others don't. I quite honestly don't use cleaning compounds much. I just wipe down.

The cleaning clothl can effect the covering. Paper towels tend to be fairly abrasive and scratch the covering. The softest I have found are Viva. I just use soft cotton polishing cloths found in the car care sections of most super stores. I prefer the flat cloths designed for high polish applications, not the terri cloth stuff. They are very absorbent, don't scratch the surface and are machine washable.

Cheers