[ESjaavik]

What is that object we can see through the oval hole?
From previous posts it seems there is a tube coming out from the frame side. But on my car there is no such tube. Nor is there any visible marks on the frame indicating there ever was one. On my car there was just one rubber spacer on each side of the sheetmetal. Or is it just a caged nut?

Measurements like this should go into a database of information here on the forum. It's helpful not only to us viewing it now, but in the future it will become even more valuable to others with cars that have been modified from their original state. It's very commendable that GTD put in a search phrase and show photos to make the measurements unambigous.