I dont think a 1/4 whip is often the best option for a CB antenna. Mounting it below metal, like on a bumper screws up radiation and swr. When driving 70 mpg and the top of it is leaning horizontal or bent like a u, i think thats a problem as well.
In theory a "102" whip would be better, and if you could mount it center of the roof, and find a whip stiff enough not to flop so much in the wind it would be better..but who the hell wants to put a hole in their roof besides me.
I would take a good base or center loaded whip on the roof over a "102" on the side or bumper.
I run a "102" on my truck, with 4 or 5 inch spring, mounted just forward of the tailgate, on the side of the bed. It just worked, had better luck with a K40 mag mount. SWR was not too bad for the lack of counterpose, about 1.3:1 on commercial grade meter. 1.3:1 at about 26.5mhz, more like 1.5:1 at 27.2, i just never got around to cutting it down as i dont really drive the truck anymore.
They need the spring on CB, and then cut down to work right.
