I'm an aesthetic first kind of guy. I figure out how I want it to look first and then figure out how to make it function that way second. So in this case I would ask what "looks" best? If you're thinking of hanging it off the brace to just avoid drilling the firewall, I'd say think about it first and go the path that looks better. Holes is holes not a big deal.I'm thinking of making a small "L" bracket and hanging it from the export brace bolts to mount the regulator and the "Y" vs drilling holes in the firewall. What do you guys think?