Thames Valley Police is appealing for witnesses or information following a robbery in High Wycombe.
Shortly before 6pm yesterday evening (13/9), the victim - a man in his twenties - took an unknown man out for a test drive in his silver Mercedes Benz from Berkeley Road.
The car then travelled around High Wycombe, and once it was back on Berkeley Road, both men got out of the vehicle. The victim was then assaulted by the offender, who then took the car.
As the victim tried to stop the offender, he ended up on the bonnet of his vehicle and was carried along the A40 for a short distance.
The victim then fell off the car and the offender drove off. It was then seen to travel along the A40 towards Beaconsfield, until the junction with Watery Lane in Wooburn Green.
The victim sustained bruising to his face and scratches.
The stolen car is a silver Mercedes Benz E250 CDI with a registration plate ending in ONS. It is possible that these plates have since been changed.
The offender is described as an Asian man in his twenties, short, of a slim build with black hair.
The officer in case, PC Francesca Keen based at High Wycombe police station, said: "This was a horrific incident which has left the victim understandably shaken.
"A thorough investigation has now been launched and we are specifically appealing to anyone who may have witnessed the incident or have any dashcam footage of it. This includes any vehicles that would have been on the London Road, A40 between High Wycombe and Beaconsfield between 5.30pm and 6.30pm yesterday evening.
"Equally, if anyone has found a discarded number plate ending in ONS or witnessed any suspicious activity involving a silver Mercedes E250, please let us know.
"Any information, no matter how insignificant it may seem, may help with the investigation and ensure that the offender is brought to justice. If you have any information, please call Thames Valley Police on 101 quoting incident reference 43170272382."
If you have any information relating to this case, please call 101 quoting reference '43170272382', or contact Crimestoppers anonymously.