New exhaust
It wont void the warranty. I have the flowmaster 50 HD series. It wont really effect the MDS mechanically but the sound will sound different when it kicks in. Just think of it as putting a deep exhaust on a v8 truck then think of the sound of that same exhaust on a 4 cyl truck. doesnt sound great but normally mds is when ur on the highway so it doesnt really matter. I really like my 50 HD series but I know there is better out there. From what I see on here most people like flowmaster and magnaflow. I got my flowmaster on Autoanything.com for around $150 for the muffler and then had the shop install all the piping. I have duals going out to the side behind the rear tires. It sounds and looks really good. Hope this helps.
It won't void the warranty. I have a true dual system with Thrush 2 chambers and an X pipe. It sounds mean under hard accel, but nice and quiet once up to highway speed.
http://www.zshare.net/audio/10504498aa60d425/
http://www.zshare.net/audio/10504498aa60d425/



