Originally Posted by mossylmk
You need a small case 25% lock lsd. Hard to find and being genuine may not be much point with a 1.6 as if you can find one they'll cost you 350 and up.
Personally, I'd try here: http://cars.donedeal.ie/carparts-for-sale/bmw-diff-gearsets/6619723
Any maybe here: http://www.bmwhaus.ie/forum/forumdisplay.php?fid=44