Hi, Am looking to purchase a cat-back exhaust for my 2000 M Roadster. I know there are several different makes out there ( Dinan, Remus, Supersprint, Eisemann ). Any one have some suggestions on which one to get? Prices vary by several hunderd dollars.... and not sure if the more expensive ones are worth it or not. Most state that the increase HP is in the range of 8-9HP. What has been your experience, if you installed one? Thanks in advance... Ron