Do you mind telling us how you broke it?
Cheapest way is to give that kit a try. Although it is for M3, it theory it should work.
RETROFITS: LCI Conversion - LCI Xenons - LCI Tail lights - Memory heated seats -
Folding mirrors with auto-dip - Rear PDC - CIC with DAB Plus - Combox - 6FL - 6NF
- 6NR - BMW live & Internet
MODS: Eibach Sportsline - AluFelgens CS7 - JBL MS-8 - Gladen components - SWS-8