only the very first ipods wont work, the version 1 & 2, which used a BIG firewire connector.
from the version 3 onwards (around 2003) they started using the current long thin connector, which is still used in the current ipod.
so if you buy a new one, it will work, no probs.
Also VW supply a little pack of plastic brakets, which are changeable, which will enable use and snug fit of either ipod of ipod nano.