Firstly thanks for all the interesting posts - in particular Didi's great intro to the process of replacing the DVD. Like many others I bought a 'backup' 2011 upgrade with maps for my 2005 Z4. The upgrade CD worked fine but the system would not read the maps DVD (but would read my original 2005 OEM version). The guy who I got the discs from directed me to this forum. So today my SM DVD-M3 4.6/88 unit arrived (I bought it from Navigatie Onderdelen a part of VIHH) and I figured I'd have a go at replacing it.

Unfortunately I'm stuck at the first hurdle. Didi says, "To open the MK4 you cut he seal at the back and remove the top cover carefully"

I'm at a bit of a loss how I get to the seal at the back. I guess through the boot by removing the back panel somehow? I guess though he is refering to an X rather than a Z? Does anyone know how to remove the unit in a Z4?

Also do I need to disconnect the battery before I start?

Many thanks..