I am starting to feel some vibration in the rear end after hard driving. I'm going to do my 60k service soon anyone else have this problem.

 

Any noise associated with the vibration? Not really enough information to diagnose anything. But some things to check are.... lug bolts torqued? Shocks bad? Tires?

SInce you are coming up on 60K there are a couple major things you need to do along with the normal 60K service items:

#1 and most important - Get your timing belt changed. After 60K you are driving a time bomb and it could go at anytime. You should be able to get this done at an independant shop for around $800 including parts, if it breaks you are looking at $5000-8000 to rebuild the engine. Make sure the whole kit gets done...Timing Belt, Tensioner, Water Pump (stock plastic impeller is probably trash, go for the metal impeller)
#2 Haldex service (I am assuming you are Quattro) and make sure you change the Haldex filter along with the fluid.