Waving at another car when you know it's driver is likely to wave back goes back to the 60s to my knowledge and prolly a lot earlier. I first found out about it when I got my Triumph Spitfire in the mid sixties. A fellow owner coming the other way on a bumpy B road near here while almost sideways still managed a friendly headlight flash. Even back then 99% of Spitfire owners would wave. If we are in the MG any classic MG we meet will wave or flash lights, a modern MG driven by an enthusiast will also do this. We have noticed over the past few years it's become more widespread and when we see Austin Healeys ,Triumphs ,Allards etc their drivers will acknowledge us in the MG. We have even had a cheery gauntlet waved in acknowledgment from a 1920s Veteran tourer. As Jug said Fiats are around in such numbers and a lot of owners are not enthusiasts so it does't happen. It's a shame as when you see a car that is a real Fiat, like a Mk I Panda, it would be great to say Hi to show that you understand why they are choosing to drive a car with soul rather than a Eurobox or an Asian Appliance car.
Oh , and if you are out on a motorcycle, even a humble 600cc Suzuki Bandit, you will get waves from most bikes you meet, although some sports bike riders wont wave to cruisers and some won't wave to Cruisers or street fighters etc etc:bang: