I regularly travel in a convoy - sometimes up to half a dozen vehicles. We tend to travel well spread out so people can easily get through the convoy. The convoy is often similar vehicles towing identical camper trailers so it confuses the hell out of oncoming traffic.
We usually all wave to other vehicles in isolated places. It is fun to see how far down the convoy people are still waving back...
My wave is usually just fingers off the steering wheel so it is not too onerous or exhausting.
Cheers
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