As you can see in the picture, the bystanders are looking at a different car. The show was about "Oldtimers" , cars that were exactly that at that time. My SL just "photo-bombed" as I was visiting the show.
One thing you have to consider, in 1982, a 230SL could have been 19 years old. That almost qualified for an "Oldtimer" and few people on the street knew a 230 from a 250 from a 280 without seeing the tag on the trunk lid.