You don’t need to take off the bumper. I copied Phil on Phil’s DIY on you tube. There’s a lot of steps but they are not too hard. There are a couple of things that I think are a little difficult. You have to be willing to tap into the wiring on your car and I didn’t really want to do that, but I did. Not hard technically, I’m just a bit squeamish about doing that to a new car. The other challenge is that the way the kick sensor works it will only open or close the hatch, not both. Unless you add a mercury switch. When Phil first mentioned that I thought no way, that’s way out of my depth. But it was actually pretty easy to make, especially since I was just copying Phil. I made one change in that I bought mercury switches that came in little black cases that come with tape on them and wiring. Make things look neater and was easier. The switch is simple, it closes the circuit one way when the hatch is up and then closes it another way when the hatch is down. The kick sensor is completely unnecessary but it gives me joy every day and works really well. Shockingly well. This isn’t the sensor I used but its the same type. The bumper on my 2021 RAV4 Prime SE is open on the back so there was easy access without removing it. I placed it a little to the right of my OEM trailer hitch. : ) (If you are happy to have the sensor just open the hatch, then no mercury switch is needed and you’ll have a kick sensor.)
The second link is to the tilt switch I used. I did a review and posted a video so you’ll be able to see my mercury switch.
Check this out! https://www.amazon.com/dp/B073HNMCMN?ref_=cm_sw_r_ud_dp_6MMQ8TQC0EX1T2M7HBKN