Jangy, it's not the tune that will break the car, it's how the owner drives it. You could severely break a bone stock car into pieces by just being tough on it.
Case in point:
I was driving a Buick Roadmaster (bone stock at first) before this MB, which shared the same powertrain/drivetrain/chassis as a 94-96 Chevy Impala LT1 (RWD). I drove the piss out of that car and really had my fun though. People don't treat rental cars the way I drove this thing. It went offroad, went racing, smoke clouds, pushed a few cars, bottomed out, went airborn, I learned how to oversteer/understeer/neutral drift in that car, hit 152mph in it, manually shifted up/down, ran all my experiments (shift to neutral in cruise control and see if it cancels cruise or hits the rev limiter), learned how to slide in reverse...EVERYTHING I COULD THINK OF!! Hell I used to kill 640 treadwear tires in 6k miles, including tire rotation too.
Now when the car was still bone stock, I broke parts..many parts. Things that don't normally break...
The Warranty stuff:
-The belt tensioner broke when I overrevved it while racing a BMW 330ci, belt tore off and broke the distributor...$1300 under warranty
-Power steering pump fried from an extensive brake/torque (overheat)
-Waterpump kicked the bucket @40k miles (high revs blamed...cam driven WP)
-Front suspension bushings
-Engine backfired out the intake...problem never found
-Rear Axle started grinding
-U-Joint failed
The non-warranty stuff:
-Complete new trans...broke so bad it was not rebuildable
-2 more PS pumps...always had a thing for burnouts
-Complete front end rebuild
-Cracked flexplate (shock from manual shifts)
-Cracked rotors AND pads
-Broken balljoint (suspension collapsed on the road)
-many many many more parts
Now most of these cars were trouble free, and this was a great car, but I admit I am the one who broke all those parts. Any car that's driven like that will screw itself over very quickly too.
You love your car and what it can do, but you just drive it within its parameters. I'm sure you floor your car off every light, but you don't abuse it per se, nor do you try to kill it. Even with your mods, you will still cause less harm to the manufacturer than someone who abuses a car.
Just to end the story about the Buick...it's still with me (vowed to never sell it because of the good times) and is getting ready to be modded again...more notably with a 6.3 liter turbo :drive: For those of you at the Pasadena Rose Bowl meet last year, I'm the one that came sideways out the parking lot at WOT
