Check out this company- dealer recommended them. Sister paid 3500 for hers for a 2006 330i.. She ended up needing over 10k in repairs and they paid the claims without any issues. Very reputable from what I've seen..
Mods: ER FMIC, AR catless , AFE dci, Cobb, HPF gen 2 exhaust, BMS OCC, ER charge pipe with Tial BOV, RB PCV valve upgrade. Waiting on Duke Dynamic D2 CF vented hood