Back in 2008, Britain's Prince Charles began running one of his cars on a substance converted from white wine. The prince's Aston Martin - a 21st birthday gift from his mother Queen Elizabeth - was overhauled in a bid to make it more environmentally friendly. The Seychelles Blue DB6 MKII Volante, one of only 38 built, now runs on bioethanol - a substance extracted from local vineyards surplus wine - which costs £1.10 per litre and is 10 per cent more efficient than using petrol. The car only gets about 10 miles to the gallon, so while it’s not particularly environmentally friendly, at least it’s using a fuel that has been re-purposed. His son, Prince William, took his new bride Kate, for a spin around the grounds of Buckingham Palace after their wedding. The car is driven approximately 300 miles per year.