I replaced all of the door lock knobs with straight ones from the VW
dealer that are similar to the ones on my 2000 Jetta. They do not have
a cap-are just straight and they drop down out of site down the hole
when I lock the doors. Unless you have the remote or a key you can not
open the door from inside or outside on my 2002 EVC when it is locked
this way. Of course they can always break a glass but will have to
climb through a window to get in and out with anything. Don't know if
this would work on your EVC, but I got the idea after someone else in
the group posted this as a reasonable option.
Miles Koppersmith
2002 EVC