When passers-by saw a Rolls-Royce Ghost "parked" at a traffic light, they knocked on the driver's door. The luxury saloon then drove off suddenly but went out of control. The Rolls mounted a kerb and got stuck over a drain, with just the left rear wheel remaining on the road, reported Shin Min Daily News. A witness, who wanted to be known only as Mr Wee, was driving past on his way to work when he saw a black car parked at a traffic light. The 49-year-old sales executive told The New Paper: "There were people knocking on the window and door (of the car). "The windows were the one-way reflection kind so I couldn't see anything inside." Shin Min reported that the Rolls remained stationary at the traffic light despite it turning green. SLUMPED The driver appeared to be groggy and was slumped in the car, which has a silver bonnet, Shin Min reported. When passers-by tried to rouse the driver, he came to and slammed on the throttle, which caused the Rolls to lurch about 50m forward before mounting a kerb. A police spokesman said the 25-year-old driver was arrested on suspicion of drink driving. TNP understands that he had failed a breathalyser test.The legal limit for drink driving in Singapore is 80mg per 100ml of blood. A spokesman for Rolls-Royce Motor Cars Singapore estimates the base cost of a standard Ghost model to be around $1.25 million.