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
'10 E92 335i , COBB