UPDATE: Disconnected the battery, left the wires off for a while then reconnected. At reconnection I could hear the satnav unit kicking into action but when I tried the firmware upgrade (after leaving it for a while to initialise then settle) still nothing

Not only that though, now the ABS, DSC and DBC lights are staying on on the dash after starting the car

I'm guessing the latter might be blown fuses but typically, after opening the fuse box in the glovebox, no tweezers present so can't pull them out to check/change

I'm giving up. Going to call the dealership tomorrow and get them to take a look. Will tell them I tried a firmware upgrade off backup CD from a mate and disconnected the battery after it went awry to try and initialise the drive, take it from there.

Thanks all for your help.

ALI