Normally, when you travel over about 20 km/hr the door's automatically lock.
I found this annoying so decided to remove this function.
Firstly, remove the glovebox, theres about 4-6 screws holding it in and clips on the left hand side, be careful not to break them.
You will see a black box on the left hand side, this controls the central locking.
To make sure you have the right box, trigger the central locking and you will hear a clicking noise coming from the box.
Cut the green wire going into the box as shown in the picture.
All done!
Put the box and glovebox back together again.
Thanks to MadYeti on SDU for the information on which wire to cut.
Dave