Linda and Donnie join forces to compete in the Greirson and Graham Targa Rally, beginning at Drumlanrig Castle and ending at Kames. It's their first outing as driver and navigator - could it also be their last? Derek 'Pluto' Murray is having fun test driving the very latest Subaru WRX STi. As a traffic policeman he would follow Subarus in hot pursuit, now it's his chance to get behind the wheel of a driving legend. Petrolhead Allan MacLeod mourns the passing of his Nissan Micra - will his Renault Megane prove a fitting replacement? And there's a damsel in distress on the Wacky Race track, with everyone in search of a hero.

Murray gets behind the wheel of the all new Citroen Cactus this week. He's never been a huge fan of the Citroen brand, so will the Cactus change his mind? He takes it for a spin across the Pentlands and over to Edinburgh to find out. Linda is in Nottinghamshire test driving the world's smallest production car - the Peel P50. It's so small it makes a Smart car look big! A Ford Focus ST is Petrolhead Mairi Ross' car of choice. An old Volvo certainly isn't Donnie's favourite vehicle in Wacky Races, despite this he's currently in the lead. Murray and Linda are determined to catch him up - will they overtake him in this week's challenge?