I said i'd keep mine at BPU!!!! but the only thing stopping me from going further at the mo is money!!
I'm sure you'll appreciate having modded a car before, that following BPU, in order to progress any further things start getting pretty costly cost when changing one thing you'll find a whole heap of other stuff will need to be done at pretty much the same time to do things properly.
Good thing is the Supe manages to keep a smile on your face even in standard trim, so modding bug is a bit easier to cope with than many other Jap high performance cars.
I've had my MKIV nearly a year, fantastic car, i try to look after her and i believe it's so well engineered that as long as maintained well should'nt give too much trouble.
Sometimes i remember when they first came out over here when i was at college and admire them, now i own one!! and where back then i used to admire the Nissan 300ZX also, i now feel time has outdated the 300ZX looks, but the MKIV still looks fantastic, can't imagine not liking it anytime soon either!!