The seat belt inertia reel (don't know a better name for it) is now mounted in place using a brace on the original mounting points. We had to cut a hole near the upper speaker. The seat belts are perfectly aligned to the belt slots in the seats. The 100mm speaker will be replaced by a smaller 3.5" model. We have ordered two frames from a Mercedes which will be used the cover the edges of the hole in the interior panel behind the seats.
The whole top had to be removed the mount the inertia reel.
DHK said:
Was it hard to change those tail lights??? I would like to do that mod. Did you have to mod any wiring?
There is quite a bit of work involved. The easy way is to follow the instructions in the BMW facelift conversion manual, which you can download here (it's in German though):
http://arethusa.tweakers.net/~femme/stuff/BMW_Z4_FL_Umbau.pdf
The conversion requires a new rear bumper, light control module, rear bumper carrier and front light units and several other parts. You will also need to update the software on the light control module. Reprogramming the light control module won't work with the pre-facelift (xenon?) head lights because the high beam is controlled by the xenon lights instead of separate bulbs.
Currently there are several German Z4 drivers working on solutions the get the rear lights to work with the old light control module and software. One of the problems they are facing is that the intensity of the tail/brake lights is controlled by PWM (pulse width modulation) which doesn't work with the LEDs in the new tail lights. Check
this thread on zroadster.com for info.
I still have the old light control module in the car. The tail lights don't work fully yet, but now that we have the BMW conversion manual we should be able to fix it.