Right, I wouldn't think they'd touch bags between airports, but for someone who is worried about the complexity of an itinerary like this, I give a couple cents for peace of mind to facilitate arrival gate to baggage claim, collecting the right bags at the right carousel, expediting to the car service pickup, and then a little extra TLC like spelling out exactly where to go once they get to DCA and all that. I don't see it as a big deal for myself, but I can see why someone may spring for services like this.