Hey man, I've been in my 07 335i since the end of this past may! Things I've noted; wastegate rattle on initial start up and for the first couple min until the pressure or engine warms up whatever causes it to stop. If you have the stock exhaust and don't do the golf tee mod then you'll have a little actuator rattle as well... No biggie, unplug the vacuum line as per every YouTube video! My mods and experience with them; JB4 Map 2 since day one (had an HPFP code thrown the first day of install, cleared the code, ran some logs to terry and never an issue since, Ps updated the firmware!), BMS DC intake (love hearing turbo spool!), HPF exhaust with stock DP's, and all I can say is the turbos even with there start up rattle are extremely effective and this thing pulls like a raped ape!!! I've been fortunate to not have any issues other than my brights won't stay on! That's electrical and not mechanical so not for this discussion! Hope this helps ya!!!
2007 335i e90 6mt | JB4 G5 | BB e85 Flash | Walbro 255lph | DCI | VRSF CP & Tial BOV | NGK Plugs | HPF Exhaust | VRSF DP's | CxRacing FMIC | Spec 2+ & SSMFW | Mtec V3 | 35/15% Llumar ceramic