When I had my CPO 08 335xi E90 with 14k miles, I was in the shop more than I would of ever expected. I was on average in the shop 2-3 times a month, sometimes 2 times per week.
This was not just one problem, everything that could go bad went bad. HPFP, LPFP, All Seatbelt Tensioners, iDrive, Eroded Cats, Injectors, Both Adaptive headlamps, Both Tail lamps, cigarette port malfunction, the list goes on and on.
What sucked was the dealer was 45 minutes away.
I eventually got to my last straw and traded her in for a new 2011 335 which had very few problems. I had it for 1.25 years and I was only in the shop 3 times.