1997 z3 radio code ?

Hi, I bought a beautiful used 1997 z3. I replaced the battery and now I cannot use the radio until I discover the "radio code" No joy from the seller. Any ideas how I can find this 5 digit code and regain the use of my radio.

Go to the dealer, should cost you about 25$.

It just happened to me and i lucked out the previus owner had wrote it down on a piece of paper and left it in the dash it was just a paper and it said "code" i also so calle d the bmw store in albq> and they said all you have to do isTake out the deck and write down the serial number and they can find it out for you