I'm in TX and tried several spots for the "sticker" from TXTag following Tesla docs to place it to the right of the rearview mirror to no avail.
I ended up getting the external TXTag, and installed it over the top of the front license plate and it works well. IMHO, I don't mind the "looks" of it, with a minor inconvenience of it covering up the word "TEXAS" at the top of my plate.