Keyser's car is quite...quiet. It sounds good, though. No drone, no rasp (that I've noticed).
However, while riding in his car, most of my attention was directed towards my brain's feelings of "HOLY CRAP WE'RE GOING FAST!!!"
Comparison to my exhaust setup - Keyser's is prolly a little quieter outside (can't say for sure), ~ the same inside.
(read: I've played with A LOT of exhausts setups, and my current setup is quiet w/ a slight hit of exhaust note under normal driving conditions)
