And there are a lot more Midgets in the world than 300 SL's, so taking a rust free Midget onto the salt isn't nearly as flagrant an assault on the sensibilities as you might think. Hell, the car that currently holds the record for I/GT is an Abarth Bialbero - when was the last time you saw one of those?
The one before that was an Abarth Zagato Double Bubble, another rare example. The current record holder borrowed parts from the previous owner.
But in the spirit of the post, the one before that was a Bug Eye Sprite....
Don't ya love Bonneville, you can see almost anything there...