hi i have a 1999 audi 80 1.8 cabriolet. just this week i noticed my petrol needle not displaying the proper fuel in the tank on occasions. It would go down a quarter of a tank and rise up eventually again. However last night the needle completely failed and dropped from a half a tank to empty working so when i completed my journey i switched off the car and lights, restarted the car and the needle on the petrol gauge worked again. Also the brake system indictor light flashes sometimes when i start the vehicle for a few seconds. i have checked the brake fluid level and the braking on the vehicle is fine too. Could this be a start of an electrical fault in the car? i heard this can be a common probs on audi's any help to resolve this?