There are currently five versions of the Hot Wheels Bullet Proof model and I currently have four of them: two from 2013, one from 2014, and this one from 2016. (I’m currently missing the clear black and gray version from 2015.) The earlier versions used co-injection molding while this 2016 version does not. According to the Hot Wheels Wiki at Wikia:
The Bullet Proof is co-molded. The body is formed by ejecting two colors of plastic in the mold. Due to cost cutting, Bullet Proof lost its co-molding in 2016.
This might explain why the base of the 2016 version no longer has the mysterious logo present on the earlier versions.