Built in Amplifier?!

I want a lil more out of my sound system, but nothing drastic. I'm happy with the head unit, as it's already an in-dash changer, I just wanted to add a lil thump. However, I was told by a sales clerk at a car audio place that the 6th Gen Accords have a built-in amplifier, and adding an amp or sub would simply add distortion. Has anyone else heard this, or is this guy just talking out of his ass?