I wish Apex would come out with actual M3P specific wheel fitments. I like a lot of their styles and their forged wheel prices are on target for being a US company using cheaper-foreign-labor manufacturing. (Which I have no problem with btw, as long as the price is appropriate.) Apex was on my short list, but ultimately I didn't see a reason to mess with Mustang fitments, when there are comparable forged wheel brands (not saying better, just comparable IMO) that offer actual M3P fitments at about the same price point. Namely, Titan7 and Martian.
I'm not saying I wouldn't ever use a Mustang fitment with rings / spacers. I'm just saying that at any given price/quality/pedigree intersection, if there are direct fitments available, those will be my preference.