That whole assembly will come out and there is a TON of space back there.That center console/cubby hole is actually 2 pieces. To get the 536 to install, I took it out and removed the upper piece (along with the flip door). That is how I got all that extra room to do the install.
I have the Larsen antenna. But it’s not cut for 42 Mhz. I wonder if I can use a separate whip for that (I have a Larsen 40 Mhz coil) using a splitter?That center storage section will actually separate from the center console. You have to pull the entire thing apart to do it. I don't have the link anymore, but you can easily find screen shots on how to do it if you do a web search. I attached the scanner mount to a metal bar that is behind the storage area using wire ties. I found that the stock bracket was too long, so I used an RH-96 remote head mount that I had.
That is a Larsen antenna. I have tried many over the years and it seems to be the best compromise for VHF to 800.