Certainly not for a 2m or the like permantly attached to the bumper or edge of hood. But I think a shorter mag mount in the middle of the hood just for the run would be fine (assuming we can solve the interference from metal limb risers). On a run, I need only to reach the leader and tail gunner. My rubber duckt on a good hand held will probably do that. I just want an ext ant for clarity and strength of signal. After the runs, I just put it inside.
I have a full roof rack w stuff attached that makes it very difficult to use my roof for antennas. I can put them at one end or the other but the absence of any ground plane to its opposite side will make almost a directional antenna.
BTW, I answered my above question. I went to the Amazon link provided on p. 2. I can get a 30' coil of 3mm in tan; or I can get a 15' length in black. The former has a 900-lb tensile strength, the latter 400-lbs. I want black; so, I'll hope I don't run into a 401-lb limb.
A new dilemma is how to secure the ends. With wire I can seize the eyes with squeeze-together lead thingys. With braided cord, I don't think that will work. If the cord is hollow, I could weave any eye splice as we do for synthetic winch rope, but I donno. There's bound to a way the marine folks secure the eye splices. I just need to find out how. I don't wanna use U-bolts that, under tension, could tear loose and make a nice head-slicer-upper.
Jerry