I'm considering the parking assist option and wanted to know more about how it works. My last 911 (993 C2S) was backed into a pole where the rear wheel fender was crushed since the car was pretty wide (I'll never let a parking attendant near my car again). Does the system beep louder the closer you get to an object or is it just one continuos beep? Are there sensors on the side of the rear which would help with the wide back of the car or are they only useful for objects directly behind?