Just got finished disabling that annoying reverse beeper. nothing new here for veteran Prius owner; but if your a part-time shade tree mechanic like me, I've got a few tips. I purchased a Veepeak bluetooth OBDII, around $15 online, Used an old android 8.0 phone w/Dr. Prius. 1. plug in your OBDII, in my case the Veepeak, and make sure the red LED is lit. 2. DO NOT TOUCH THE BRAKES, press the start button twice. Check the dash board, it should light-up in the "not ready" state. If it states accessory on, hit the start button again. 3. pair OBD II bluetooth to your phone. if this is your daily phone; you should first unpair or disable communications from your phone to the car. 4. Once OBD II is accepted in your phone's system menu. Launch the Dr. Prius app and select OBD II. It should connect and the Dr Prius options menu should pop-up. If you didn't unpair your car from the phone; this may take a minute - your phone's CPU is busy processing all the other data your car is throwing at it. 5. Select the 4-5th option down, "Other", and check the disable backup beep box. Back out of the App and give it 30 seconds. Turn everything off; then restart the car, and test. Reverse should only be a single beep now.