OP sorry for your bad experience...
but honestly my E90 was tuned to the teeth running 20psi in the midrange, FBO + meth + E85. not a single issue (worth mentioning). Never ever was I bummed out becaus3e of maintenance. Change a water pump once and oil gasket once that's it.
I demodded my car, and now it's up for sale. No rattle, no noise no nothing. I love it!
I bought a 2010 335i N54.
I'm on my second N54 now... to be exact I COULDN'T GET MYSELF TO BUY ANYTHING ELSE
SOLD --'07 E90 335i, PTF COBB E50, HFS4, ER CP, ETS 7", AA DP, Vishnu Exhaust, DCI, ACT, Nitto Nt555
SOLD '10 E92 335i M, 6MT COBB v3, ER IC, ER CP, VRSF DP, Fuel-it st2, Mfactory LSD