Not really the same. This is about adding resonators, etc, to change the actual exhaust note as heard inside the car, as well as actually piping fake engine sounds through the car stereo. When you put a Cherry Bomb in a car you heard the same sound as everyone else around you (and boy did they hear it).
Oh yeah...that I know. But technology has improved a lot. Back in the day there were few ways to go. Hell...it started with baseball cards (doubles ONLY) in the spokes with a clothespin.