I think there is plenty of room for dealers who want to make profit on the after-market sales. Especially as we're moving into the world of digital music. A new breed of customers is emerging where they're not bound by the old school luddite thinking, but are instead heart-and-soul into the convenience of streaming their music on demand, wherever they are. The next wave will be browsing and streaming lossless music from your library into your car.
People will want to have that capability, but they won't know how to go about it. Just selling them hardware and software will not be good enough. They will expect service, and the way vendors are, the service will most likely be shitty.
This is where I see a potential niche for knowledgeable audio experts to walk in and make a killing on charging for the after-market set up and whatnot. Very minimal risks (no upfront investment, no inventory), potentially huge profit margins.

