I'm also in Burlington County. I've never gone back to the dealer...but if I had to I was going to try Holman Cadillac on 73. My dad uses Burns ex-Pontiac/GMC on rt 70 in Marlton for his Trans Am and hasn't had any complaints that I'm aware of. I plan on taking my GXP back to Tune Time in Lakewood for any maintenance I can't do myself.
2009 G8 GXP, 6M Sport Red
Kooks 1 7/8" Longtube headers w/ JetHot Silver
Kooks high flow cats
SLP Skip Shift Eliminator
SLP 160* thermostat
Rotofab CAI w/ dry filter
HP Tuned @ Tune Time Performance 394rwhp/385rwtq