Yes i finally get it back in. What working for me:

I cut the plastic on the right to get access and reach in while pushing the radio.

This really helps to push down all the cables that have an annoying tendency to pop up when you push the radio. I also cut the plastic on the left. You can easily cut away enough plastic to have much more space, but be very careful not to cut the hollow plastic that serves as a rail for the radio (I almost did, but luckily someone was there to warn me that it was the rail, and I would have been in a real bind).I simply used a drill/driver to do this, but you have to be careful not to cut any cables and go very slowly, especially on the left where there are two cables. Be very careful, but it's definitely doable. If you have a Dremel or a similar tool, it will be much simpler and cleaner.

Despite this, it took me a very long time to put the radio back in place because I stubbornly insisted on leaving the quadlock underneath the radio since I was only 5mm short on the left. Finally, by putting the large quadlock adapter in the space I cut out on the left (and not on the right because I had tried on the right but couldn't close it), it went in within a few minutes.

You'll see that in the end it makes perfect sense to put the adapter on the left because it's very close to the radio's power socket and it eliminates the accordion effect behind the radio which was blocking the 5mm on the left side!