Just picked up a 2008.5 Black mica GT last month. So far just Rota tarmac 3's in hyper-black, tint and black emblems. Dont know about performance mods, want to keep my warrenty. Really enjoying her so far fun little car, I'll post a few pic's.
Gauges would be nice, cant believe they will try to void your warrenty over a safety item.
I just asked mine about a boost gauge he said it would void the warranty, I told him well the car should have come with one he agreed but still stood behind saying that even a boost gauge will void it. weird.
edit. oh and btw nice car looks good in black.