For "roving" in VHF-UHF contests, it's very common for folks to have multiple VHF-UHF-SHF beam antennas (yagis, quads, loop yagis, quagis, etc) installed above the roofs of their vehicles, on rotators, and not only drive 75 mph with them that way but also frequently use them while in motion.
Yes, the indicator is usually wrong unless you happen to be driving due North or something, but that doesn't really matter much. What matters is making the contact.
If you view this web page and scroll down to the photo of a whole bunch of rovers parked side by side you can see what is done. I had a 10-band "rover" rotating platform on the roof of my van for two of the contests: 50 MHz through 10.3 GHz, inclusive. All the antennas mount to a "box" containing all the transverters and amplifiers, with masts clamped to the box, and the whole affair mounted on a rotating platform, rotated by a simple Yaesu G800SA rotator. And it all survives highway speeds presuming you don't hit any tree limbs!