Got my quad kill this morning on Armored Shield. Had some mines set down elsewhere, then was bombing about on the quad and someone drove over them. Boom. Achievement Unlocked.
And then, as is completely typical, about 10 seconds later I was roasting it past the gunship control point (B I think), went over a bump and went flying straight into an enemy engineer who was standing in the middle of the road aiming his stinger.
"Wha's in cherge here?"