At approximately 11.30pm I left Alton Barnes, driving towards Honey Street. The weather was wet but not raining.
As I reached Honey Street, I could see some bends in the road ahead, shown by the light from my headlamps. As I neared them, I saw an approaching bright white glow from further down the road, beyond the bends. I assumed this was a car approaching from the opposite direction and slowed down in preparation.
As I neared the bends, a single, bright headlamp raced around the corner in the centre of the road travelling at approx 50-60 mph. I thought it was a motor cycle, although the light seemed lower to the ground than a headlamp. Perhaps a foot to 18inches above the road surface.
Seeing the excessive speed the object was travelling, I actually stopped to allow it to pass me, still assuming it was a motor cycle.
As it became only 10-20 feet in front of me, instead of swerving to go around me, the object suddenly changed direction at a tangent to the ground and flew up and over the roof of my car. As the object flew (approx 10 feet above the roof) so the car stalled. This was not caused by my error as I had stopped and the engine was idling. The car has never stalled in this situation before. Although the engine stalled, presumably due to electrical failure, I did notice that my headlamps remained on during the experience and that I did not notice the brightness drop. As soon as I was aware of what had happened, approx 5-10 seconds after the object flew over the roof, I wound down the window and opened the sunroof to look behind me. The object had totally disappeared. As the object flew over the car, I noticed that, unlike a headlamp which shines light from one side, this object seemed to be emitting light from all angles, although the light was so bright I couldn't make out the shape of the object due to the glow surrounding it.
I then drove back towards Alton Barnes to see if I could see where the object went to, but I did not see it again.