Exhaust shop is your best bet, or if you have a friend with a welder who knows what they are doing. Or just get one of the cheap $140 apexi knock offs on ebay. They sound good, fitment is just off a little.Here is the exact one I got and two years later it is still doing great.
http://cgi.ebay.com/ebaymotors...t_754As for the rear tire noise... look under there and just look for anything out of the norm, Bends, Breaks, and maybe a bushing missing..