I have a 2000 Buick Rendezvous with an audio system that insists it is "locked". This is due to battery problems we had a couple weeks ago. I believe the car's serial number is 3G5DB03E22S510050. I'm not sure if the 0's are zeros or letter O's. If you could give me the unlock code and tell me how to use it I would be eternally grateful! :D