I had a dealer fitted reversing sensor which was fine when I picked up the car (had to make a quick stop at a garage as it was running on fumes) and when I got home from the dealership, but when I went to collect my daughter from her school drop off, putting the car in reverse just had a constant beep tone rather than actually warning me as I got nearer to things. When I got back home the car did the same thing. When I go on a longer journey it works fine, but there seems to be a pattern that if I use the car for a short journey (say less than a mile), when I select reverse I get the continual tone. Has anyone experienced anything similar? I'm going to take it back to the dealership but I just want to check my theory on drive distance is correct first as this is likely to be the kind of issue that appears intermittent and difficult to fix as a result.