Just fitted a VW PDC kit (one of the rebadged Cobra units that the dealers use) and it beeps like a madman as soon as I stick it in reverse, whether or not there's something behind the car. Have calibrated it 3 or 4 times on 3 different walls with no change! Pretty much useless as is it is, scratching me head a little bit about what I've done wrong...
Too much paint on the sensors? Too low to the ground? Any ideas welcome