B5 A4 D90 question?
 

So i am new to the whole wheel and tire game, i usally never replace my wheels from what comes on the car however i am working on a project and really like the look of D90s. i have been told that because the rear wheels and larger than the fronts i will need something (spacer, adapter) to run them on an AWD car. any advise fro the wheel gods would be helpful. the car is a B5 (99) A4 avant. 1.8t Manual Quatro