I just got my Z4 for my 28th birthday (16255 miles in excellent condition from one owner!) and I am very impressed. This is my third BMW (currently own 06 330i and previously owned 03 325i) and with out fail it drives to my expectations. This car has every option except NAV and AT. Good acceleration (sport mode) and remarkably quiet. My wife was very impressed after the test drive and we got it! The car makes a better impression in person, than through pics. Interior is nice with remarkably good space, especially the trunk. Now we have to wait for the spring (live in MD) to truly enjoy it, but that doesnt prevent us from driving it on the weekends!
Sport package (especially the sport mode, why turn it off?), xenon lights, power soft top, premium sound, red heat seats, exterior and interior design.
My cupholders rattle when they are inside the dashboard, other than that, no complaints for now. BMW should have made the 2.5 a six speed as standard option. When cruising on the highway its doing about 4000 rpms (85 mph), which I think is extremely high. Shifting is not as smooth as my 06 330i.