1/4 wave antennas are very broad banded, so they work well when you have a lot of spectrum to cover and want to keep reflected power reasonable (low SWR).
An approximately 6 inch tall 1/4 wave UHF antenna will work surprisingly well.
They are also a great solution if you have a commercial UHF radio and are using it to cover GMRS, LMR as well as the 70 centimeter amateur radio band.
Not hard to get 50MHz or more of useable bandwidth out of a UHF quarter wave.
I ran a 5/8ths wave vertical for a while back when I had my GMRS license. Worked well, but SWR was a bit high on 70cm. Mine didn't have a spring, so it was a little stiff. On the roof of a full size 4x4 truck, it was a bit of a hazard with low branches.
I replaced it with a 1/4 wave, and I couldn't tell any difference in performance on GMRS, but I lowered the SWR when on 70cm. On the flat lands, I had no issues getting 15-20 miles of range simplex on GMRS. Since I have a lot of hills and mountains around me, quarter wave tends to be the preferred choice when repeaters are above you and the horizon isn't that far off.
1/4 wave antennas, especially on UHF, 800MHz, etc. are -really- low profile. On top of a full size SUV or truck, they just about disappear. Plus, they are really inexpensive.
I run quarter wave VHF antennas on my truck now. With a commercial radio I can easily use it on the 2 meter amateur band as well as my work stuff (up above 158MHz). Putting the antenna on a proper analyzer shows low SWR from 144MHz well up towards 170MHz.
Here's the plot from a VHF quarter wave. 2.0:1 is a pretty good SWR number to stay under, so that's where I placed the markers. You can see 2.0:1 is easily done from 138-170MHz:
Here's a 5/8th's wave VHF antenna, you can see it's narrower useable bandwidth (and rises pretty fast):
If all you are using is GMRS, then a higher gain antenna is fine, if you don't have clearance issues. Any issues with repeaters being above the primary lobes of the radiation pattern are probably not going to be any sort of issue. The benefit of lobes launching off towards the horizon can be a benefit out on the plains, but I suspect you'd have a really hard time hearing the difference unless you were really right on the fringes of coverage. Another slight downside of longer/higher gain antennas is that they'll bend back when driving a highway speeds, which doesn't help radiation patterns much. A VHF or UHF quarter wave won't really do that to any noticeable effect.
The big benefit is that you used an NMO mount, which gives you the widest selection of antennas. That makes it really easy to swap out different types of antennas depending on what you need. Considering you can pick up a 1/4 wave UHF antenna for about $6.00, it might be a fun experiment.