A speeding driver has to pay £11,000 for challenging his ticket after a prosecution expert hired an airfield and a sports car to prove him wrong.
David Pickup, 45, was clocked doing 101mph in his Audi R8 on the A55 at Lloc in Flintshire in April 2014.
Flintshire Magistrates' Court heard a police speed camera caught him and he asked officers: "Can we call it 98?".
Pickup, from Wilmslow, Cheshire, who has a holiday home in Abersoch, Gwynedd, was convicted of speeding.
He denied breaking the 70mph speed limit and questioned whether it was his car that had been clocked.
His defence counsel questioned the accuracy of the in-car police speed camera so the prosecution hired an expert who rented an airfield and an Audi R8 to carry out tests, the results of which were presented to the court.
Pickup was fined £675, given six points on his licence and ordered to pay the full prosecution costs - which included the testing - of £10,384.