If you have SatNav system then it's worth waiting for the SatNav drive to stop before disconnecting the battery. The drive activates as soon as any door/tailgate/boot is opened. If you disconnect power before the drive has stopped initialising then you run the risk of corrupting the eprom memory.

Open the boot, wait for 10 minutes, disconnect the battery.

Oh and don't forget to return your questionnaire to Tim to get full access.

Nich.