what should i have the dealer check immediately before warranty expires 2000 - 36k miles

Hmm...get them to give u some free goods....This is what i got/did
 

Before u go out the door, have them replace spark plugs, HEPA filter, Oil change/filter. Air filter if u don't have a K&N. Have them replace the brake pads, front and back. Top of fluids like brake and washer. Get them to replace your wiper blades. Any recalls have them fix. Have them vAG it and get a copy of all the codes(if any). Demand an alignment(audi gives a free alignment every year under warranty)also with a copy of the specs.
That's should be it....Get some free stuff from them, because after the warranty goes Pouf, The parts department is a dark cold place to be standing asking for prices, and NO free loaners.

DG