Hi my wifes car is having same prob maybe the washer tube froze and spilt so water is leaking on the sensor you may fine your alarm goes off random as it thinks the boot is not shut i found this forum which is the exact prob i am having so i'll give it a clean and a check tmrw 7/01/11
try this link cut and paste etc
http://www.golfgtiforum.co.uk/index.php?topic=35509.0
Andy H
January 2011
The hose for your back window washer is dripping down onto the switch that displays the messege on the onboard computer. You will need to take off the whole back door panel and dry it out and reconnect the cable to the washer firmy to solve this.
Regards
john
john hudson
March 2008
I can answer this question...
how can i fix my vw golf tdi luggage compartment warning light?