Place: a motorway. Time: one of those occasions when you see stranger cars. Like: a colourful cavalcade of Vauxhalls from the Vectra Enthusiasts Club. A Saab convertible with the roof down. A Subaru Tribeca. An old XJ6 in police livery. An Audi obeying the speed limit. I was in it. The car you see here. The latest 5 Cabriolet, a four-seater delight, even in bridal white.