Originally Posted by elm3
Sounds like the idle is too low at 600rpm, it should be more like 750rpm, if I'm not mistaken. Low RPMs will make your engine sound rough. So it could be your RPMs. Try to take it to the dealer and see if the can adjust it.
+1, 600 RPM is too low IMO. Should be around 750-800 at idle. Just bite the bullet and take it to the dealer. They'll be able to tell you for sure.