Brand new to the forum. Just purchased a 2005 660. I want to put a hitch on it and have read threads on how to do so, but when I went to look at the bolt holes, it appears there are some sort of plugs in there? They don’t have much of a head on them and I cannot tell if there are threaded or pressed in there. Ill attach a pic. Can anyone tell me what I have going on here?

Thanks much, and I am looking forward to reading more on the forum!

Nick