The Smart TOP is a great addition to the Z4. It is nice to be able to program just what you want the car to do when you lock it up and what position the windows and mirrors will be in and the walk away top closing are all good features. The ability to choose what speed YOU are comfortable with the car in motion and raise or lower the top. It is the best mod for the Z that I have found so far.
'11 OS E89 Z4 (Sold)
'10 AW E92 M3 (Sold)