HI  bought a Fabia estate 1 TDI 80 2009  yesterday today i noticed that when i switch the side/headlights on the boot unlocks and stays open wile driving it bounced open, 

i pulled over and it would not close and lock wile the lights where still on once i had turned them off it closed properly as soon as i turned the lights on again i heard the boot unlock 

 

any help most appreciated 

Scan it for errors with a VAG COM interface. The very last days I've found that the boot lid unlocking mechanism is on the same circuit as the interior lights. I've burned the fuse for the interior lights when I was installing speakers in the trunk and after that, the boot wasn't opening by pressing the outside button, I've had to pull the lever next to the driver seat. You might have a short to the ground somewhere IMHO.