This achievment can be earnt in about 15 seconds easily from start to finish, without needing boosting partners, without having to search for EMP grenades, and without having to do it in multiplayer.
The only requisite is that you have finished the Decipticon campaign up to the last mission.
Select easy, and load up Chapter IV - The Death of Hope, Checkpoint - Terminal Ambush.
Select Soundwave as your character. He has the leader vehicle with ram, despite being the scientist class.
As soon as the checkpoint loads, walk 10 steps down the steps. Right in front of you is a set of 3 EMP grenades.
Turn right, there is a door 10 steps ahead of you. Open it.
Inside are lots of cloakers.
As the Ram is not a one shot kill always, shoot the barrel right in front of you. This will damage the cloakers, but not kill them. Toss your EMP grenade to roughly where the barrel was and you will see 3-4 cloakers stunned (and at low health 5meters ahead).
*Please note, so that the AI will not charge into the room and start killing things, shoot the barrel as soon as the door opens, then toss the emp grenade as soon as you stop firing. This way you will have everything done before your team-mates join the battle. - Thanks to McDurbin for that.
Hit transform (LS), press boost (LT) and then tap ram (RB).
Achievment done, in a grand total of 15 seconds.
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