Adding a mesh wind deflector
The mesh wind deflector can only be fitted to Z3s with roll hoops. The parts retail at £90 (against £180 for the wind deflector for Z3s without roll hoops). Fitting takes just a few minutes and mainly consists of removing the two tenax studs that the tonneau cover connects to and replacing them with longer versions (left hand picture). The front of the wind deflector has clips that hook under the plastic near the rear speakers (right hand picture).

The previous version of the wind deflector had clips front and rear.

Here's an article on MZ3.Net which you might find useful.

.