When the car is freshly detailed late afternoon with the windows up, AC blowing cold, crisp reflections gliding against the shiny hood while listening to nice music and relaxing one hand on the armrest.
When another DIY project has been successfully completed, and going for a short (test) drive.
When at a Benz meet with fellow w123 enthusiasts lined up on the highway taking videos and pictures, passing and signalling each other as if in a choreographed move.
When walking towards the parking lot and instantly seeing my car amongst the white, silver and black cars, especially on a bright sunny day.
When, right after doing an oil change (almost due, by the way), I check and double check to make sure the level is correct, everything else is accounted for and I've just wiped clean the valve cover of any spilt oil, I know the car is ready for another 3,000 more miles.
When going through a winding mountain pass going left and right, well balanced and sure footed, then realizing the old girl still has it in her despite her age. Then going back for another run!
I could go on and on...