Mark Kermode presents from the Aardman studios in Bristol to celebrate the 20th anniversary of Wallace and Gromit's first outing. Celebrity fans including Terry Wogan, Jonathan Ross and Ian Hislop discuss how they fell in love with the clay characters, and creator Nick Park explains his inspirations. Actor Steve Martin also talks to Lauren Laverne about his passion for banjo, bluegrass music and his band's first UK gig at the Royal Festival Hall SUB HD