Do all Class A gas MHs have generators in the back?

OK...I'll chime in... my genset is mid-ship in the compartment just forward of the driver's side rear tires. Exhaust pipe exits just in front of the tires beside the main engine tailpipe. Surprisingly, to not be a "quiet run" set, it is remarkably quiet. But I do not ever plan to sleep with it running. Just too many risks of CO buildup inside the coach. Even with a detector, I don't trust going off to LaLa-Land while it's running....I really don't want to wake up dead...