Nice car. I’d get myself an OBDII reader if I were you, then use it to clear your faults and deal with the codes that reappear via Google, YouTube and this forum. The one I use is Veepeak, available on eBay in conjunction with Bimmertools which you can download for a small, once only fee. YouTube has plenty of DIY videos and tutorials that’ll put you on the right track to either do the work yourself or understand what your mechanic is talking about. Good luck and happy motoring with your new BM.