If you decide to hard mount later on, the ideal, all around location for an antenna is the middle of the roof.
Since height can be an issue, mounting on the back of the vehicle is the next best. Not on the bumper though due to grounding and continuity issues. Mounting to the spare tire carrier can be a similar issue. This is if you are using the vehicle as your grounding plain. Also, location is going to focus the beam in the opposite direction.
So, if mounted on the right, rear, the strongest transmission and receive signal is going to be to the left, front. Great for highway travel.
The antenna also needs to rise above the vehicle to prevent the vehicle from acting like a shield and causing a blind spot. What that height is, I can’t say since I went with a stainless steel whip.
I would do some research to figure that out so you can get the best performance out of what mounting options you have available.
I believe there is a mounting bracket that you can use that bolts to the tailgate hinge. It might take some research to find the right bracket. Best performance tends to be something that bolts right to the body sheet metal.