There is conflicting information on this, however the last three digits are the series of the build spec rather than the VIN. I assumed that the dealer and GM parts could figure this out, but they were not able to do so and thus the blank badge. I'd be very happy to be wrong on this, but honestly I could have far worse problems with the vehicle.Jack Tors: please see #11 & 12 above. Pretty easy to see what it should be. 4(1 or 6 auto or manual)-(last 3 of your VIN)