"He shot across the road. But it was so close that if I hadn't emergency braked I would have gone straight into the middle of his car.
"As I put on the brakes, my car span towards the central reservation and smashed into it. I clipped the curb and buckled the wheel arch of my car. The airbags went off and there was smoke coming from the engine."
A spokesman for Buckingham Palace has confirmed that a royal household vehicle was "indirectly involved in a collision on June 2".
He added: "All the relevant details have been passed to the police."
Meanwhile, a spokesman for Sussex Police said: "Police were called to a collision on the A27 at Firle around 8.30pm on Sunday 2 June.
"A vehicle collided with the central reservation close to the junction with Lacys Hill, reportedly after avoiding colliding with another vehicle. No injuries were reported and enquiries are ongoing."
-Bang! Showbiz