VIP Protection and traditional law enforcement are completely different concepts. The doors are opened slightly to create a balance of having cover of those officers in the car and being able to exit the car and form a line of defense for extraction in the shortest time. Also, during an ambush, the attackers are usually more focused on the VIP, not their protection too. In traditional law enforcement when you are taking fire to duct and get behind cover. However in VIP protection, you are the cover for the VIP. Hence why the doors are opened slightly
So from your stupidity it's normal for Donald trump to have excort vehicles but not China just because the video is title BULLET ? U people are too easy to brainwash
I dunno, if you need several SUVs of security and a bus of troops to keep you safe just driving down the street; Maybe you arnt making the right decisions on behalf of your people.