2010 Accord Chassis question, what goes here?

[GreatCanadianMoose]

Changing the struts on my daughters 2010 accord EXL, 2.4l auto, and I noticed this empty threaded hole that isn't rusty inside, in fact the thread inside looks like shiny metal as if a bolt was just removed.

Looking on line I can't really find what should have be bolted there so I can figure out is there's something missing or not???? Some of the videos for oil changes and exhaust repair that show that area seem to have nothing bolted into that hole but like I said, it's rust free inside and looks like shiny silver on the threads where it's bare metal, rusty all around the outside but clean inside, canadian car driven in the winter... not much under here can be described as clean.

Thanks
M