We've all been there when our children erupt into full scale road rage while we're in the middle of traffic or on a long road trip. I think you'd all agree that it's not the best place to reason with them or let them eventually peter out. Believe it or not this just happened to me a couple of days ago where my 10 year old was in the midst of a temper tantrum and my nerves were frayed. I'd been running errands in the escalating heat all morning long and then had two doctor's appointments and wouldn't you know it, my son wasn't feeling well and just that morning had had his favorite toy taken away from him for a few days for a punishment involving a bad attitude towards his sister so he was still upset about that and this all led to him erupting at one of the worst moments possible.
My first inclination was to talk him out of his temper tantrum but he wasn't receptive to that in the least. When he was smaller I used to play his favorite digitized CD on our ipod but with him being older now, I put on his favorite radio station. Recently I read an article discussing this very thing where the author suggested mymusiccd.com. Their products use their child/children's name in their music and stories, which automatically distracts your child out of their temper tantrum into quietly listening to the CD. Their little My Music CD ships personalized music, personalized books, personalized stories and personalized sports play by play CDs all over the world.
Another effective tool is dialing it in. The low-tone cell phone ringtones can be very soothing. Some mothers swear by the heavy drum and bass tones.
For younger children stockpile some magnets. Dig out an old metal cake pan or small cookie sheet and load it up with large magnetic pictures or letters (they should be larger than 1 3/4 inches in diameter). The magic of magnets can mesmerize them for hours. I've included some toy magnet sets below. You might want to order a few sets because you're never too young or old for magnets and you can distract them for hours not only in the car but while you're at various different appointments and meetings as well as at home too and this way you'll have them on hand for hours of entertainment. What a heavenly way to have a precious me moment or time for two (daddies love time for two if you catch my drift! :O))
Here are some activity books for their amusement and distraction in both the car, at home. and for while they're out and about at appointments, etc.