My "Ghetto Mount" Garmin. I had it wedged in there with the clip, but found that it tended to bend the plastic cubby making it difficult to open. I took the clip off the GPS and it sits further back in the cubby but works fine. Now if I could just get power to it so there's no cable showing... I have it plugged in to the port on the driver's side with a Belden USB converter and a mini USB cable.
I have thought about finding a small bean bag, attaching a piece of velcro to it and the back of the Garmin in order to give it a bit more weight, though so far I haven't had any issues with it falling out of there. It's just a bit unstable when punching buttons on it.
Hope it helps!