VW battery?

so my mom has had three batteries in her new beetle since she bought it in '01. 4 year old car, three batteries. this isnt normal.

dude at the VW place told her she has to lock the doors every time she parks, because otherwise the computer continues to run, and drains the battery. i smell bullshit. its not in the owners manual that this happens, and id think something as important as that would be. and i just dont see what locking your doors has to do with the ECU.

anyone know whats up/ have similar problems?

Unless you lock and set the alarm, the comfort system keeps power going to all the other computers in the car. And yes, vw's do eat batteries like fat kids eat candy, especially if you let the car sit for long periods of time (aka over the winter stored)