Not much actually, regular maint has cost me an arm and a leg this year, I had to turn the rotors and do some other unnecessary work to make sure she was ready for the trip to Orlando (FFW Spring Break Shootout) last month. I also had to buy some new rear tires for the trip as well (big surprise there). Those 18s are not cheap... I think that I put the blowoff valve since you've seen it, and I also had to put on some adjustable upper control arms because I broke one of the heavy duty ones I installed last year. Now I have to buy a aluminum driveshaft because its vibrating very bad above 70mph. I wish all of these issues would stop popping up so I could actually invest in some new parts. The reality is.... the faster you go, the more you break