Just finished the installation of a set of Fabworx Performance downpipes along with new spark plugs, aFe pro dry air filters with charcoal filter delete, and a Bootmod3 stage 2 91 octane flash. The car sounds and feels amazing. Not excessively loud at all and you can really hear the turbos spool up.
I read a lot about which downpipes to go with and I can attest that I had zero fitment issues with the Fabworx pipes. No cutting or modification to the heat shield was required for me. Message them on Facebook and they may be able to hook you up with a good price.
I had the pipes Cerakoted before installing which I couldn't get a definitive answer as to being required or not, but with the cost of these cars/motors I opted to spend the $150 to coat them for a peace of mind. So I would recommend that.
I replaced all the hardware/screw clamps/gaskets using this diagram linked below. You do not need to replace item No. 6 which is a spacer flange. Make a note that there is a gasket on the turbo shown on item No. 5.
https://www.realoem.com/bmw/enUS/sho...diagId=18_0952
Below is a link to a picture of them installed.
https://www.amazon.com/photos/shared...EWV2CuK5OxSsJ0