got my new 2007.2
 

Havent loaded it yet...does anyone know if I can go back & forth between the new & old by just putting the desired disk in??

How old is your older disk? They changed the format of the address book along the way, so the disk may work but stored addresses may be an issue.

Not sure which version it is...I'll have to eject it from the mk4. Right now the car is at the dealership for an OS upgrade. They are doing it free of charge. They usually charge $150!