Found a random bolt with washer still attached sitting next to my fuse and relay box. I think it matches the hole in my pictures. My car has never been serviced, just got it June so it must be from factory. Can someone else with an RX 350 please show a picture of the same area, I feel like there may be a component missing since the bolt doesn't seem to secure anything, but it does fit. It's the only thing I noticed that was missing a bolt.

 

I would send those pictures, and your question, to my dealers service department.

 

No, that's not it. That hole is also blank on my 350. Look around carefully in that same area and lower, that same bolt holds the front engine cover on for example.