Richard Hammond celebrates 40 years of the Porsche 911 by taking the super-fast GT3 to the limits. Clarkson tries out Ford's latest supercar, the GT. Meanwhile, James May tries out the new BMW 5 Series. The Star in a Reasonably Priced Car is Martin Kemp. And watch out for the spectacular way the Stig in Top Gear's 20-year-old Jaguar meets a watery end.