The BMW 6 SERIES (2010-15) 640D 2DR CONVERTIBLE 3.0 DPF SS 313 EU5 SE AUTO8 is a large, four-seat luxury convertible, sitting above everyday coupés and convertibles in the UK used-car market. Its long, elegant shape and folding roof make it a relaxed grand-touring car rather than a practical family runabout. In mycarcheck.com data, this model generated 180 lookups covering 66 distinct VINs, a snapshot of buyer interest. The average private-sale valuation was £12,300, while the average recorded mileage was 81,000 miles and annual mileage 5,000. Checks also showed an average of just over three previous keepers, so reviewing each car’s history is worthwhile. Its 3.0-litre diesel delivers brisk, effortless performance and can be economical on longer journeys; the automatic gearbox makes cruising easy. Roomier and more luxurious than an Audi A5 Cabriolet, it suits couples or drivers seeking open-air touring. Rear-seat access and running costs are less than a saloon.