Correct...there aren't any RCA jacks, but if you hook up a multimeter you'll see that there is a 2v signal going through them to the amp under the seat. The MS6 has the same setup and I tapped into the signal by removing the factory amp under the seat. No need to pull apart the dash. Just make sure you don't mix up pos and neg leads on the RCAs because things will sound pretty funky if you do.
~ Chris