I would find a good NMO mount and drill the hole. NMO is what the vast majority of public service vehicles use. Done properly, it is watertight. The antenna can be unscrewed and stored when not needed (or in a garage)...
Second option would be to bring the existing wire down the back of the cab into the vent behind the back seat and into the cab. Still leaves a lot of wire banging against the truck at road speed.
Another option would be to mount it in the bed or on the back bumper and run the wire underneath the truck, through the firewall, and into the cab.
Running it through the window or door will work on a temporary basis, but will eventually crush or break the cable. It also tends to leak when raining, as the water will run down the wire and end up inside.
What type of radio are you connecting?
Second option would be to bring the existing wire down the back of the cab into the vent behind the back seat and into the cab. Still leaves a lot of wire banging against the truck at road speed.
Another option would be to mount it in the bed or on the back bumper and run the wire underneath the truck, through the firewall, and into the cab.
Running it through the window or door will work on a temporary basis, but will eventually crush or break the cable. It also tends to leak when raining, as the water will run down the wire and end up inside.
What type of radio are you connecting?
