I always wave to other zeds, sometimes even frantically flashing lights and hand out the window wave in excitement.
I also give a wee wave to the rare s-chassis and r-bodys I see on the road.
I noticed a very clean twilight blue HR filling up at my regular shell garage. As the lady drove off, she noticed me filling up my zed. I gave her a very nice smile and a nod of the head. She turned away and drove off. I then realised there are two types of zed owners :/