I'm planning to convert the exhaust on my S3 90 Spider with Motronic to a header and perhaps Ansa muffler. I keep getting different answers from the traditional suppliers and know someone here must have done this before. My plan is to install an aftermarket header, cat bypass, and an ANSA rear muffler only. Can anyone give me specific suppliers and part number for the header ? That seems to be the only item that suppliers disagree on. Thank you.