The best route is to buy either a good used or refurbed 296, then go buy the car kit. I paid $999 for a refurbed 296 from Marv Golden (no longer available), and added the car kit. It is a lot of money even so, and I look sometimes at the investment and hang my head, but man is the unit sweet to use. I am thinking about an AirGizmo once we pull my ADF out this winter. But truthfully, it is pretty nice mounted on the yoke too.
One weakness to be careful of is the power cords. They sometimes seperate where the connector to the unit goes into the cable strain relief (rubber cover). I complained to Garmin and they are sending me a new one.....but I was able to rebuild the old one so will have a spare. Pretty good service considering I expected to pay for it.