does anybody know how to work round a immobilser and alarm on an A3 my key doesnt seem to work anymore

 

I think it's easier to change the key battery. Or try your second key. If you're planning to steal the thing, you're gonna need someone working at an Audi dealership that can get you a key cut, and the VIN number.

 

Cuski; LOL. My sentiments exactly.
Also - it does not matter if you know someone at the dealership - you will need that plastic tag that the keys came on - it has the information for the chip programmingin the key toggle. Man, I didn't realize that until I had read the manual and had throw out that tag. I had the garbage dumped out in the driveway and was furiously looking for that thing. Overall, without all of those items - good luck.