I've read on quite a few posts that the rear's don't need to be upgraded, just the fronts. I struggle to get my head around that. My car just reached 40k and all of my pads and discs needed replacing. Both the front and rear discs were at minimum thickness (-2mm from new).
If you only upgrade the fronts, I assume you will replace the rear discs and pads several times for each set of fronts. Do you live with that because they don't overheat on a track day, and that’s the main concern?
I'm not sure how they don't overheat... The rear pads have a smaller surface area, on (practically) the same diameter disc. On my car both fronts and rears eroded the discs at a similar rate. The rear pads were even more dead than the fronts as well. That suggests to me they may even get hotter than the fronts…
Anyway, jealous of the OP. 👍 I toyed with the idea of an upgrade but couldn’t quite justify the cost. Especially I’d really want both ends done, for cosmetics if nothing else. And I’d need wheels. And Coilovers. Enjoy your BBK!!