Revealing mistake: When Fi triggers the bomb under the car, in the shot showing the explosion, the bomb itself, with an obvious red flashing light, has disappeared, plus the explosion originates from within the car, rather than underneath where the bomb was placed.
Last Stand - S4-E18
Revealing mistake: After Michael blows up his car, the bad guys' car hits it and pretty clear jolts to a near-stop. In the reverse angle it suddenly smashes over the top of the burning vehicle at great speed. Not to mention that without a ramp there's no way it could have jumped the wreck anyway.
Chosen answer: They could wear disguises to hide their appearance.
raywest ★