Jeremy Clarkson and Richard Hammond tackle the twin problems of an ageing population and the increasing complexity of modern cars. Their solution is to design a vehicle exclusively for the elderly and then test it out in Dorset with a little help from a trio of pensioners. James May assesses the new Range Rover around London and then shifts to Nevada for the ultimate challenge against an autonomous military machine. James McAvoy is the star in the Reasonably Priced Car.