Originally Posted by claykin
Are you referring to the corner of the VIN decal? That "B"# has nothing to do with production date.
If you want to get an idea when you car was produced you can either check with dealer SA or just look under drivers seat and find decal on side rail near carpet by center console. This white decal has the build date of your seat. Seats are JIT production so this pretty much represents the assembly date of your car. I suspect you'll find your seat has a date code around 26-11-2012.
My car was produced November 8th and my seat says 07-11-2012. PW45.
Even better stick your VIN in bmw vin decoder and get the exact build date