Here is my breakdown of the various options:
Easiest option by far = FRS.
A pair of
GOOD FRS radios should reliably reach 1-2 miles under most conditions (I'm talking about ones that boast about "35-miles" or greater range... It's quite doubtful you'll actually get 35 miles talking car-to-car, but the numbers are still relative when comparing units). Stick a few AA cells into each unit (or charge them up if thats the type you have) and you're now on the air and talking to each other (though you probably ought to pick a channel other than the default of 01 (and set a privacy code) if you want to minimize the number of others you come across on the channel).
2nd-easiest = CB.
Contrary to the jokes many here continue to make about CBs, their range is far better & above anything FRS can offer (or any other handheld radio used portable inside of a vehicle, ham or otherwise). Range is reliable to about 5 miles, and frequently can hit 10 miles or more with a normal 4-watt output radio.
CB does require you have a decent antenna, and is where most people that diss on it made their mistakes... You should avoid at all costs any CB antenna that is less than 5 feet overall length, and mount the antenna up high where it is in the clear (top of roof is best, but a bed-side-rail or fender/quarter mount can work fairly well too if the majority of the antenna is still above the vehicle).
The radio unit itself is less important, however avoid the Cobra 75 radios (has an exceptionally poor microphone built into it/poor sound quality over the air), a Uniden PRO-510XL/520XL sounds 5000% better, both on transmit
and receive. Those that absolutely must have a handheld all-in-one type CB unit in their vehicle will be far better served by the Midland 75-822 than a Cobra 75.
3rd-easiest option = MURS.
I put MURS 3rd because of somewhat-limited MURS radio availability/having to (correctly) program radios for the channels (you may want to also enable the CTCSS (a.k.a. privacy) tones... in some areas on occasion I have encountered bleed-over or brief pulse-type noise interference on various MURS channels). Most 2M ham radios are also useable on MURS with a modification made to the radio. Some legal technicalities exist with using a modded ham unit, however if everything is properly configured (freqs and modulation type set correct, power level set to within reason), i don't think anyone would be the wiser (radio software such as Chirp has the MURS channels already preloaded (in addition to FRS & GMRS), which can be downloaded to most radios. This should help simplify programming of a radio for MURS).
Range typically is 4-7 miles using the legal 2 watt power level w/external vehicle-mounted antennas. 2M ham antennas cut a few % shorter work great on MURS.
4th = GMRS.
GMRS requires a license, but there is no test. It costs $90 last I checked, and is good for 5 years. Use of repeaters is allowed on GMRS, which are not legal for use on the first three options (and would not be of practical use on CB anyway).
Range (simplex) is about 1-5 miles handheld-handheld, or about 3-10 miles w/hard-mounted units (it varies widely with terrain due to the line-of-sight nature of the UHF band GMRS uses).
Finally = Ham
If you're technically-inclined, you may find ham easier than GMRS, simply because the cost for the license is much lower (usually just a small fee for the examiner's time), and fiddling with a radio often comes naturally. The technical aspect of ham can be difficult for some to grasp though, so you'd have to judge for yourself whether you're up for tackling it (remember whomever you talk to has to be licensed also, unlike on GMRS where family members/those living in the same household of the licensee are covered under the same license). Ham is also the most formal of all... don't forget you have to ID with your call sign every 10 minutes so everyone knows exactly who you are, and (among other things) no cussing! lol
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Anyway, hope that helps.
I'd lean toward a pair of good decent FRS units given the OP's requirements (Motorola's --350R series radios or something similar). Only if you think you'll need to engage in conversations with others on a regular basis would I consider other options (#2 being the most universal, though I always try to promote the use of #3 also).
*** gmrs through the baufeng is not technically legal, however, adjusting output to low power, brings it awfully close.
Well, since you brought it up, neither is it on MURS or FRS. Additionally MURS (1-3) and FRS require the modulation be set to "narrow" mode as well. How many people have actually been popped for using a Baofeng on these services though, I'm not sure... It would seem to me it's a fairly low number (probably consisting mostly of egregious violators who cause problems, often deliberately, to other users/users of other radio services).
