The boot lock in a 2003 Volkswagen Passat is a tiny piece of metal on the boot lid which latches onto a hook on the bottom of the boot. When this boot lock no longer works properly, the boot no longer opens automatically (without manually going into the boot and unhinging the latch) or closes, both scenarios causing the car's owner undue frustration. In order to repair this problem, you will need to change the boot lock.
Open the boot and remove the 13 screws around the perimeter of the carpet lining.
Remove the carpet lining from the boot of your Passat.
Disconnect the actuator rod from the boot latch. The actuator rod is the metal rod that leads into the boot latch.
Remove the two 10mm bolts from the sides of the boot latch and remove it from the car.
Place the new boot latch onto the boot lid and bolt it into place using a wrench and two 10mm bolts.
Connect the actuator rod to the new boot latch by snapping it in place.
Place the carpet lining back into the boot and secure it in place with the 13 screws you removed in Step 1.