The site is hard 2 navigate easier to just email them but here's the link
http://www.res-exhaust.com/p-460295c...74387a285.html as for the company itself I never heard of them and it's rather expensive I would go custom but here are some pics if you search res racing exhaust e84 on YouTube u should see some videos as for the diffuser u would have to modify the oem one like in the picture