what equipment does the quattro system use?

ex. differentials (where?) (center, front, rear) stuff like that

and will e-brake 180's mess up my system?

 

ebraking will have a negative affect on your drivetrain. The only time to do it is in the snow.

 

A4's use one mechanical/helical center differential made by Torsen. the front and rear diff's are open. audi uses edl to reduce wheel spin which relies on the abs system. e-brake is a bad idea considering that the front and rear split is 50/50 and it doesn't change to much from that. You will only cause pain and suffering.

 

I've been doing them in the rain ...is that alright for the differential with using the e-brake....?

 

No.. not really. Even worse for your wheel bearings.

 

any way to replace the front and back open diffs with helical, or viscous? how about a 2 or 1.5 way?