My rear wiper does not work,or automatic boot opener?

could be that the earth connection is at fault.some vehicles use hinges for the earth connection between tailgate and body. after a while rust and usage can make connection faulty. try running a new earth wire from tailgate to a good clean earth point in boot [there will be one for rear lights]and see if this cures your fault. also the multi connector pins and connections may need a good clean up.[these are near boot catch.]
hope this helps.

k
September 2011