I did the windows and the front of the trailer.....you ought to SEE the diamond plate at the bottom SHINE!!!! I went right over the decals, no problem. The trailer is new, so I did not use any cleaner --- and I would be VERY careful with any abrasive cleaners any where near the decals --- the 845 just shined them up......I once got some STONERS window cleaner on some of my decals, and it melted the decals, so I understand your question very well!!
You will LOVE the 845 on the paint, windows of your truck and canopy as well. I've never seen a product that is this inexpensive, you use so little, it goes on and off as easy, lasts a long time, repels water....well, I could go on...
Its available through both Amazon and eBay....one of the sellers is offering a free microfiber towel and applicator pad, as well as free shipping for $16.95 for the 16 oz bottle.
You use so little that you could do your truck 15 times with one bottle...