i took out the original BMW stereo from my 95 525i about a year ago and put in an after market stereo. however, now i want to go back to the original and put in the after market one in the other car. as far as i remember, to turn the radio back on ill have to get a code to "activate" it. is that right? how do i get one? do i have to go to a dealer (and pay them?) for this or is it something i can find somewhere based on the VIN?