Trunk lip mount
I have used this type of mount with my ham radios on my last four cars with good results. Chose your antenna first so you don't have to use any adapters between the antenna and mount. Check the path for the coax to be sure it doesn't have any sharp edges or sharp bends. The only problem I have had is feeding the coax on one car. The space was too small for a cable with connector like the ones used on most mounts. I had to cut off the connector and soldier a new one after running the coax. Be sure the the location does not allow the antenna to hit the roof of the car when you open the trunk. Check the screws regularly, especially the set screws that hold it on the lip of the trunk. I put a small amount of dielectric compound on the threads of the connector to make removal easier and to seal out moisture. Depending on the trunk seal, you may need some type of drip loop to prevent water from entering the trunk where the coax goes. Leave some slack in the trunk so that suitcases or other items don't put a strain on the coax