I've seen this pop with almost any vehicle AL kill, Mongooses seem to be the hardest to drop, but ghost drivers seem to love giving this achievement away, although cocky banshee drivers have too.
As said, breakpoint seems to be the map of choice for this, indeed, It's where I got it too, there seem to be 2 strategy's to this:
1)
Bait the driver with some DMR fire, and he'll most likely try charging you, drop into armour lock about a second before he hits, and you should get a nice fiery explosion to mark your achievement.
2)
Play dumb, face away from an approaching ghost like you've not seen him, natural arrogance and the possibility for a free kill will lure him into splattering you, keep an eye on the radar, and engage your lock when you see him approaching, the sound of him boosting his ghost should be fairly obvious too, this is especially effective if you strafe, then stop, like you're scoping in on something.