No place to install an after market fuel filter. Personally with what you said in terms of roads and more importantly fuel quality I would avoid the 335d. For reference it uses the Bosch CP3 injection system or so I've read.
Sent from my MB525 using Bimmer App
Current: 435i, M-sport, MPPK, MPE, ZF8HP
Previous : e90 335d, e90 330i, e46 330 zhp.