IMHO, all of the top brands should do the job. In South Florida, many of the shops use XPEL and SunTek. Last September when I priced out allover PPF for my Z4 the majority of the shops quoted me in the $4,500-$5,000 range.
When they see an expensive car like the M8 they tend to quote more money as they assume that if you can afford to buy a car like that you can also pay top dollar for PPF.
Negotiate!!!
