Review on Dorman 746-509 Door Lock Actuator Motor for BMW Models - Enhanced Compatibility and Performance by David Stover

I installed/replaced door latch actuators on my '99 Z3 2.3 Roadster 2 months ago. So far they are working perfectly. As someone else said, definitely consider fixing plastic window panes while you're there! In my case the slides were intact but without lubrication. This fixed the slow window movement and (fingers crossed) prevented the slide motor from having to be replaced. The actuators were a little tricky to swap out and I accidentally bent the actuator rod the first time I tried to remove them. TAKE YOUR TIME! Read on if this is your first try!