Thank you for clarifying the proper procedure. The audible warning signal can be silenced by pushing the reset button, the one in the middle with the dot. You have to silence it each time you back up.
I have a 2021 RX450h. Owned it for 13 months now and am very happy with the vehicle and plan to keep it long term. I've discovered that I get a little bit better gas milage running regular grade gasoline through it than using factory recommended premium fuel. Haven't noticed any engine pinging. Why shouldn't I continue to run regular fuel?
If you have a 2021 or 2022 model, it will require that there is a trim cutout on the appearance panel to install a receiver hitch. Here is a photo on how it looks. This is on my 2021 RX450h.