Yes ,It would be more like a transmission line than an antenna I think.
I have at the moment on the roof racks ,a 4m long plank (aprox13 ft),a 3m long plan(10 ft) a 4.5 m long aluminium ladder.It just seems like too much aluminium too go to waste ,not being used as antennas
The plank only sits about 6 inches off the roof. Its difficult to have a mobile antenna on the roof as I always pulling things on and off the racks and an antenna would be in the way.
Im not too interested in mobile ops at the moment anyway ,as my licence class only permits 10w pep. Gotta get off my a$%#@ and upgrade.