Plot: Fifth Gear checks out London’s most exclusive supercar rental club, the Segrave Clubparks, and parks three of their cars — a Lamborghini Murcielago LP640, a McLaren Mercedes SLR, and a Porsche Carrera GT — on the street for 10 minutes each to see which turns the most heads. Jonny takes a BMW 635d, the world’s first diesel grand tourer, to Poland in search of cheap diesel