The adapter you've got isn't made for pullout stereos. I've got the exact same adapter in my Mustang with an empeg and single DIN Pioneer navigation system. I had to take a dremel to one half of the adapter to enlarge the opening for the empeg. As far as I know there isn't an adaptor on the market that will do what you need without enlarging one of the openings. I can take some pictures of my setup this evening if you want.

-Mike