I was able to mount my TRX-1 first in my Honda Civic and then in my Dodge Journey after I replaced the Civic. I'm going to give you an overview of what I used, but you can cobble together something that will work for you.
I prefer dash mounts, since I use the cup holders in my vehicles. In the Civic, I used a Panavise dash mount, but unfortunately Panavise scaled back the vehicles they make mounts for many years ago. For the Journey, I used a dash mount made by
Pro Fit International. Since I also have a Yaesu FTM-400 mounted in the car, I used
this bracket from Lido Mounts to mount the FTM-400, with the plate vertical instead of horizontal. If you turn the microphone mounting plate upside down, so the round notch is at the bottom, it holds the scanner by the belt clip just fine. Lido sells everything individually, so you can get the mic / belt clip holder separately.