I didn't realize you were in the DFW area. I have a couple of the Mequire's products (both claybar types too-- they sent me a professional clay bar and paint cleaner for free since I had problems with their original clay bar), and my bro has a lot of the Zaino stuff. I'm sure we can do a "test" area and see which will work best, maybe even clean it real quick for ya. In the meantime, DEFINATELY email Meguiar's and ask them. I've emailed them before on things like this. Try to tell them what type of paint is stuck onto it in case that matters.
Also, their paint cleaner is a clear-coat safe rubbing compound, although they deny its a rubbing compound. [:)] I also have some 3M clearcoat-safe and non-clearcoat-safe rubbing compounds. Do it by hand or machine. Machine is quicker, but can rip through the paint if you are not careful.
You can also wet sand it, but if you go too far, you can only do so many wipes before it cuts to the paint. Keep that in mind for future scratch repairs, so you know how far you can go.
Speaking of scratches, I have a couple new ones on my bumper cover now, since the dog's claws scraped through my cleacoat! AHH!