HI! wounder if any one could help me on this! audi a4 1999 saloon,brake light and tail lights working on same bulb but they have their own seperate bulbs/ circuit.when i switch on lights the tail lights come on and so does the brake light in the rear windscreen.When i press the brakes the tail lights come on as the brake lights,so driving at night i would have no brake lights. appreciate any help....