Most of the emergency type CBs have antenna that have telescopic antennas that are not suitable for use while driving. They are also very difficult to use as in there is not microphone, you have to pick up the entire thing and hold it to your face. They also do not have good speakers. I would certainly avoid these items.
Like was said, a cheap CB can be had from garage sales for under $1. If you were closer to me, I would GIVE you 4 or 5 CBs. I have boxes full of them. Dunno if they work, but I use them as rifle targets. I have accumulated many over the years.
Couple that with a cheap magmount antenna from RadioShack, and you would be set for under $20. Toss it in a tupperware container in the trunk and you are ready to go. And it would preform a lot better than the emergency setups.,
WM