Ok, so there's alot of misconception here... I am a Professional truck driver. I'll mention the misconceptions one at a time:
1) engine (Jake) brake laws are antiquated. New big rigs (roughly 2007 (maybe a smidgen earlier) to current date) are inherently so silent when engine braking, you really can't tell there is engine braking at all. These laws are for older trucks that have been grandfathered to not require mufflers. The laws were to combat noise pollution. Big trucks also down shift while using the engine brake itself to slow down, and in a lot of cases, rarely touch the brake pedal when done correctly. Even without the actual device itself, we still refer to it as engine braking because we literally use the engine to slow down when we don't need the engine brake [device]. The officer must prove that you were actually using a Jake brake.
2) Double clutching has nothing to do with engine brakes nor slowing the truck down. You can actually shift a big rig without EVER touching the clutch pedal. It is called "Floating Gears". You SHOULDN'T float gears in a car, but it isn't impossible. I do it often in a car. In NORMAL passenger cars, you don't double clutch because they have synchronizers that prevent the need of it. You can tear up your transmission by double clutching a car [that has synchronizers].
3) Cars don't have engine brakes. They don't need em. And VERY FEW diesel pickups have them, cause they too don't need them.
4) Someone mentioned dynamic braking using the cooling system and it [dynamic braking] has absolutely nothing to do with the cooling system. It's primarily used in trains to help the locomotives slow down... Dynamic braking is used in electric motors. Not internal combustion engines. It's the high to low RPM's with no throttle and the car's low weight after shifting that slows the car down (the motor wants to idle, so the low weight of the car causes a much more rapid deceleration than a big rig, where the mass of the big rig wants to keep the rig going, and over-rides the engine's wish to idle).
5) all of the terms in reference to the Jake brake are synonymous... Jake brake, engine brake, compression brake, etc are all the same thing.
EDIT: Please stop down-voting my answer and editing it because you don't THINK I wrote it correctly. I wrote the answer how I wanted it to be written. Thanks.