For the wheel question start here, look up wheels for both cars, and see if they are the same.
www.tirerack.com
Call them they will ans. your questions. 877.232.8699
My guess is yes, but that is only because they are both VAG vehicles.
Check out this forum, it is "the" forum for your car.
http://forums.vwvortex.com/forumdisplay ... V-Jetta-IV
The tech page with lots of relevant information, more options at the bottom of the page.
http://www.tirerack.com/wheels/tech/tec ... ntpage=101
Good luck, a vwvortex member.