After doing the install I actually am not going to remove the backing from the front grill, and thus I am going to keep the license plate in the stock location. See my install images here
https://photos.app.goo.gl/uqgfIwIX5vw2QJjd2
I did get a response from Rho-Plate using their "contact us" on their website.
Their response:
"We can look in our inventory and see if there is anything that fit if you can get us some dimensions on your car.
We need to know the thread size of the tow hook, if you know the spec of the threads please let us know, or you could place the tow hook beside a ruler and take some pictures for us to measure the thread size. (High res preferred)
It will also help to have a side and top view of the tow hook installed in the car so we can judge the length of the mounting bolt required."