Although I've never driven a 35i it would definitely feel a step down for me, build, refinement, drivetrain etc if I went back from my M135i to an E89, all about the drive at the end of the day, still miss the E89s looks though 
The Z4 just needs an update to bring it in line with the rest of the model range.
Tim.
The Z4 just needs an update to bring it in line with the rest of the model range. Tim.