Overview: Tiff Needell flexes the muscles of the mighty BMW M5, with its 400-brake horsepower, 5-litre V8 engine, and assesses its chances against the opposition of the Jaguar XJR and Mercedes E55. James May is in America to sample some startling concept cars from Chrysler, including the Dodge Charger R/T and the Citadel. Chrysler has a history of making dream cars become reality, as demonstrated by the Viper and the outlandish Plymouth Prowler.