Re: I got offered 15 grand for my mazda3.
well, if they offered your friend 30 grand for his civic (no civic, short of the Mugen Si, has EVER been worth 30k), then I'd bet they are assuming all mods stay on the car.
Personally, I wouldn't bother with it, unless you are actually in the market for a new car. KBB trade-in is $14.5, so they aren't offering you THAT great of a deal on it, especially if the aftermarket stuff has to stay.
2004 Velocity Red Mica Mazda3 S
Leather, Sport package, Xenons, Nav., Speedline grille,Koni Yellows, and 17x7 Bronze Racing Sparco NT-R's (15.3 lbs) wrapped in 225/45-17 Dunlop Direzza Z1*/Mazda Millenia 16x6.5's wrapped in 225/50-16 Hankook Z214 C71's