beeping alert when hatch open

Having owned our Prime for 2 years, I finally encountered a situation where I had to load a long object (an 8-foot orchard ladder) into the car. It fit easily except that it projected about two feet beyond the interior. I did not have to go very far and it was easy to secure the hatch using a couple of short bungee cords between the license plate frame and the bottom latch.

Appropriately, the Prime alerted me that the hatch was open -- and beeped constantly when the Prime was in motion, falling silent only when stopped at traffic lights.

While I don't have any plans to do this again any time soon, I was wondering if there is any way to silence the warning beep in this circumstance.

Also, we are considering installing a hitch for a bicycle carrier. Will having a bike on the rear of the Prime cause the back up sensors to issue warnings and/or cause inappropriate automatic braking when the Prime is in reverse?