The n54 doesn't scare me at all (knock on wood). I own one out of warranty and plan to keep it for awhile. I'll maintain it... The things that sort of scare me on the car are all the electronics (adaptive headlights, etc.)... The engine isn't a concern at all hpfp is covered to 120k. Even off warranty, what's it cost at an Indy shop? A $1000? That's really not that bad.... Turbos cost around $2500 to replace these days, which would be crummy, but they don't seem to truly fail often, just rattle.... Small prices to pay for how fun the 335 is... The electronics are shared with the 328 so we're all in the same boat on those.
I think the average person expects to do to maintenance to their car which may work on a Honda/Toyota... Not so much a BMW (or any other European car for that matter). It's all a matter of what are ones expectations of the car...
Jet black e92 6mt 335xi:
18" BBS RGRs, KW v1, ESS Stage 2 flash, VRSF 7" FMIC, VRSF downpipes, JG Mods m-tech front, mtec V3 AEs, BMS OCC, hardwired valentine 1, p3cars gauge, amber delete, sport seats, factory oil cooler.