Or what modifications necessary to install on vert cars of the ones that arent "bolt on"

I didn't think headers were effected by convertibles, I thought it was the axle back part of the exhaust where there is a cross brace for added support? That is why GM put the crimp section in the exhaust.

I'm about to find out. I bought Kooks 1 7/8 LT's with catted mids, the borla 60606 mid pipe and the borla 11925cb atak axle back with npp for my 2016 convertible. As soon as I get done with the latest round of mods for the GTO, the Camaro will be put in the garage for it's long list of mods.