Out of interest farrar, do you have the techno pack on your car?

No I don't have the tech pack on mine, but you definitely have a wiring fault if the front and rear lights are coming on with the headlights on off.
 
this seems to sound like an option in VAGCOM

3.12 DaytimeRunningLights(DRL)
Component: BCM PQ25 (09 - Cent. Elect.)
Byte: 23
Bit: 6
Purpose: Switches on the low beam as soon as the ignition is turned on. This way low beams are always active. The rear lights, city lights and dash lights will NOT come on. Unless you have a Light switch with 'auto'- option and it gets dark enough :)

so can also be turned off