When the car is turned on the car idles a just under 1k rpms, goes down after a long while or when youdrive the car. Since its a 1k when i put it in drive the gear enters preaty hard, if i put it down to Nuetral it usual goes down to 700rpms.

What could be causing this?

 

Not exactly sure but I'll take a stab at it. Get some Sea Foam and try cleaning the TB out and the IAC ports. It helped my friend's blazer. He had a low idle. Stupid question but, you've never messed with the set screw for the throttle plate did you. That throws a LOT of crap off.
I had an argument about that with some KID one day. Moron

 

May be normal.

The stock programming for the A4 sets the idle speed at least to 900rpm in neutral, until the coolant exceeds 111degF, then tapers it off to 850rpm at 132degF, 750rpm at 154degF and then to the "hot" idle of 650rpm when tem exceeds 176degF. With the typical error in the stock tach, it wouldn't be unusual for it to indicate 100-200rpm higher than the actual idle speed.

Sounds like it would be a good idea to leave it in neutral for a few seconds before you pop it into gear.

Does the idle speed drop if you tap the throttle? Do you have a high idle at any time other than cold start?

 

Just noticed that my volatge kinda drop while driving the car, maybe the alternator has something to do with it because when i move it to a gear it dips a bit causing the check guages light to come on , then i put it in nutral an dit revs up a bit. I was told the car revs up to keep volts at 13some.