Modifications and warranty
 

If I get a new exhaust system will this void my warranty? Does the exhaust need to be installed by Nissan service center or could the auto sport place do it themselves?

If it is a cat-back exhaust, it would be extremely difficult for them to deny you the warranty since it does not interfere with any sensors or puts any additional strain on any part of the car. The only advantage to having the dealer do it is that you can get it in writing that it will not void your warranty since the work was performed by them.

/\ +1. It'll probably be more expensive to get the exhaust installed at the dealership though. I would discuss any mods you'd like to do to the car with your dealership and see what they say about it. Some dealerships are pretty good about honoring warranties w/o a hassle and some are terrible. Shoot, our Nissan dealership has installed stillen S/c's for at least one customer that I know of so it all depends I suppose.

Regardless, a catback really can't do anything that could cause warranty issues.