Yesterday, as I left the house my fuel gauge was reading 1/4 full, I drove 1/2 mile and stopped, when restarting the car it showed empty and the fuel warning light was flashing. The odometer was reading 345, I know that I normally get approx 380 miles to the tank full, so off to the petrol station it was. This has happened before but only between 1/4 tank and the red, but has always returned to normal whilst driving. Any ideas? or has anyone had this problem?. The car is a 53 plate 1.6 twinport SXi, which is still under warranty so it looks like its back to the dealer.