Just unlocked it... and i've attached an Xbox One Game DVR to show you how it unlocked for me.
You need the China Rising DLC (Available today for BF Premium Users, 12.03.13)
I was playing Conquest [Large] on Guilin Peaks.
There are dirtbikes everywhere.
Grab a bike and get to a busy conquest flag spawnpoint.
Get into 3rd person view (it was easier for me to do it with that view) line up the enemy and run him over. Note: If you're playing 'Hardcore' you can't get into 3rd person view, you'll have to drive the dirt bike in 1st person view.
Look for snipers, a lot of these guys panic and switch to pistol, but by then, you've ran them over.
Good luck and have fun!