Camera batteries have died on me.
But on my car I have 6 holes evenly spaced along the sill at 9.5-inch intervals with the first hole from the front end starting at 5 3/4 inches in.
The holes are 2 inches down from the top edge of the sill.
Some of my holes have been filled in by a body man in a hurry but most of them are still there. I use them to inject cavity wax.
There is also at least one small hole that looks like it might have been a sheet metal screw holding at least one front corner down. If there were others they were probably filled in. It may even have been someones attempt at repair if the origional fixings had started to come away.