Going from the old style key fob to the new style B7 fob is a nice relatively cheap and easy upgrade.
You need a B7 remote with matching frequency to your existing. Used OEM B7 keys go for as low as 23 bucks on ebay. New Chinese knock offs go for 20 bucks on ebay.
You need a key with an FCC ID : MYT 4073A 315mhz 8E0 837 220
Immo Chips can be had here:
ID48 chip required
The main difference is the ebay ones require reprogramming every time you disconnect the car battery or replace the fob batteries. OEM stay programmed throughout, but needs one thing.
The used OEM will need a new blank key blade. Where the knock offs come with a blank already.
Both will need the blades to be cut. From the stories I've read online(I'm paraphrasing here), IF the dealership is willing to touch your blade, they send it off to a desert in Europe, apparently to a skilled basket weaver that lives in a house for fun, who then ships it to an unknown PO box in Belarus to be inspected by a troll, who rolls a deltoidal icositetrahedron, that determines if the fathers will grant permission of such witch craft to take place. If so, he'll wrap the forged metal in a black magic carpet back to Germany, which actually acts as a time machine to when the merger of the four companies originally took place in 1910 to form Audi. to then be cut by some young engineering student for 190 bucks, which is cheap given the process it goes through.
Or you can goto your local lock smith, call first, and they can do it for 15 bucks.