I spent the better part of two months experimenting with ways to do this, and unless you cannibalize one of the DIN radios with the front-accessible release, I think you are going to have to scrap the idea of using the DIN mount as it is. It just doesn't give you any way to access what is behind it.
What you can do is cut the mounting flanges off of your mount, then add tabs to retain it behind the panel with the passenger seat indicator and behind the HVAC surround. You might want, or have, to use the flanges to hold it forward, basically captivating it between them and the panels. At that point it will work the way mine does, giving you easy removal of the radio after the HVAC surround is removed.
Here are some additional pictures of what I am doing. I think they are fairly self-explanatory.
Sky NA 2007 Midnight Blue
Sky RL 2008 Carbon Flash - Naked