I just recently purchased a 07 Chevy Trailblazer, well actually my dad got it for me for graduation, and I plan on working on it first adding audio visual.
But my dad got the extended warranty as well which covers bumper to bumper for 3 years i think. and he said as soon as I add something it will void the warranty, so he's not letting me do anything to it.
3 years is a long time to wait until I can actually work on it so I was wondering. Does it really void the warranty if I add sub woofers and new speakers.

If the adition of the AV equipment causes damage then it probably won't be covered. Otherwise I'm sure it will be ok. What I mean is if the engine blows up then I don't think the AV stuff is going to have an effect on it.

A lot of times its up to the mechanic to make the call about stuff like that.

yeah that's what I was thinking as well. I'll just keep trying to convince him.
thanks

It shouldn't be a problem unless the new speakers go out. They will not fix aftermarket speakers, but if you blew out the OEM's they would most likely be under warranty.

With Chevy's bumper-to-bumper, your stock system is covered. If you throw in an aftermarket system, your audio is no longer covered by the warranty. Everything else stays covered, unless it can be proven that your new audio system over-loaded your alternator, then you're paying for an alternator replacement. (You won't have this problem unless you're running 3+ subs, over 1200 watts in terms of amps, a couple of caps, and more.)