Listings are here:
http://www.ebay.co.uk/itm/BMW-M-Perf...item2c8e5e77b9
And here:
http://www.ebay.co.uk/itm/BMW-M-Perf...item2c8e5e77b9
The second link is what is supposedly for the 428i although it shows having dual left/right exit.
What I actually want is the diffuser to fit the 428i but have the dual exits like the 435i has. I've got an exhaust in the pipelines from milltek which has a dual left/right exit like the 435i...!