klippa fra annet forum:
"The SMG system (actually SSG) is rare, and so I suspect it will be hard to find anyone that can work on them down the line. It also limits your performance upgrade possibilities by adding an extra complication.
Problems with any pre-facelift models are rare, if you eliminate the squeaks and rattles common to convertible ownership. The electric assisted power steering can develop problem in hot weather, and the power tops can fail if exposed to water, which occurs when the drain holes get clogged. I suspect this is rare when the car is garaged, and so doesn't collect a lot of debris like leaves and twigs.
Other than that, the Z4 is essentially a re-bodied E46 3-series, with similar upgrade options and similar foibles. You hear less frequently about window motor failures, though - the Z4 has smaller windows for one, and the motors see more frequent use, which I suspect helps prevent them seizing.
Recommended options are Xenon headlights, heated seats, and sport package. Nice to have are M-sport seats (not to be confused with the standard sport seats), premium package, and extended leather. The navigation system is a personal choice - it's considered too primitive to be useful by most.
My "best buy" recommendation would be a 2004.5 3.0i with sport package, heated seats and xenon lights. Among the cheapest Z4s with more standard features than the 2003, and when/if you swap the headlights for clears you don't have those annoying little front reflectors. Swapping in a 3.46 diff would put this car on par with the performance of a 3.0si for less than $1000."
ang. sportsseter har jeg hørt både positive og negative ting. en av de negative som oftest kommer opp er at de virker veldig "flate" og harde. bra sidestøtte, men hardt på rompa og ryggen på lange turer. men det er bare en ting å gjøre; prøve selv