16:00The 4 O'Clock ShowBookshops, Eco-Films and Rupert GrintBBC Radio 4 Extra Duration: 1 hour Tue 19th Aug 2014, 16:00 on BBC Radio 4 ExtraIncluding the Norwegian student who lives in a cave and how the film industry is going green. Plus, Richard Hammond reads the next instalment of Chitty Chitty Bang Bang.GenresEntertainmentBrandThe 4 O'Clock Show Source: BBC Online