Craig Charles and the team celebrate the 400th edition of the technology programme, with Georgie Barrat building a birthday cake out of smartphones and 3D-printed buttercream. Jon Bentley heads to Paris to put the latest sat-nav devices through their paces, while Ortis Deley compares tech available when the show began in 2004 with the Apple iPhone 11. For the grand finale, the presenters embark on a mission to reclaim a world record they once held - for the longest jump by a remote-controlled car.