This is a bit of Extreme Cyborging microworks: how to make a car floor mat stay in place with sturdy, cheap materials?
As people that are totally into "testing" prosthetic arms for any reason - most "testers" do not build better solutions anyways, so why waste so much time for "tests" when they could have a perfect day on the beach instead? - on top of all drama lack knowledge of what it is that "we" do, day in and day out, here is another example of what we ("we", as in "disability microaggressions") do. At this stage, it is fair to say that there must be millions of other arm amputees that do not perform any such things. Not a bit would they do such a thing such as fixing their floor mats to the car in such a nifty way. So if you after that what "the millions" do, nothing to see, circulez svp.
The actual problem at hand (darn it, he wrote "hand"!!) is that the Subaru mount points do not reliably hold the Weather Tech floor mats in place. The mount points slide out of the mat holes all the time.
So I drilled two extra holes into the floor mats to allow a cable binder to force the Subaru mount point in place by pushing it upwards, permanently, from underneath the mat, into the hole(s).
The following image shows the Subaru mount point (black plastic strip) that now cannot escape the floor mat as the cable binder pushes it into its assumedly correct position, all the time, or, permanently. The blurred hook is a hook, that I use to mount or install these things - so I guess that was what you came here for? There you go, hook.
I added more cable binders to make sure nothing slips here.
You may trust my narrative in that I subsequentially clipped them.
That makes it less elegant to just pour the dirt out and one has to resort to a sponge, or, vacuum cleaner. But I eventually got to vacuum the rest of the car anyway so no biggie.