I would not recommend using the mk3 unit from the rover, it has a locked OS, so will accept no updates, go for another mk3 or a mk4.

The problem is that the guys who did the battery/alternator change did not follow the power down procedure for the mk3, they have corrupted the drives ROM.

I read at least one of these every other week, people who don't know what they are doing working on these cars...

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Sept 03, M3, Silver Grey. Retro-fits: Modded Mk4 DVD Drive, OEM Bluetooth, VR Control, Rainbow Speaker Upgrade, Sony SOT Amp, HK Sub, CCFL, Intravee II, NightMode.