This is what I used:
https://www.amazon.com/dp/B0CQLC4P4S?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
The corners were a little tricky to get to stick correctly, but I eventually got it. I might need a touch of superglue on the bottom corners, but overall it looks great in person. I did a test cut with the original hitch cover panel before I tried it on a new one because it was already broken, so I was going to have to replace it anyway. I ended up buying the new cover panel from the Lexus dealer in Mobile, AL. It was the best price I found.
I just used a Dremel tool with cut out wheel for plastic. It cut through it like butta.

Oh, and another tip, make sure you use tape to mark your lines so you don't damage the finished side.