Britain's Secret Shoppers (2013 - 2013)

Justin gives Jan a crash course in how to haggle thousands of pounds off the asking price when buying a car. He also goes undercover in The Dollshouse, run by glamourpuss Cat and her pal Mark, who need some help with their sagging bottom line. And Which? reveals some raw deals at the supermarket with our recommended five a day.

Would you have the confidence to walk into a designer boutique and ask for money off an impressive frock? Justin helps two label-loving ladies haggle money off just such a frock. Three streetwise London cabbies hit London's hi-fi stores looking to bag a bargain. Justin goes undercover at a second hand car dealership in need of a jump start.

Justin helps a soon-to-be wed couple get the deal of the century, saving thousands of pounds on their dream kitchen. He explores fixed-rate mobile phone tariffs with the team at Which? And turns secret shopper to help one of the country's oldest coach firms, whose trips are so undersubscribed they have to cancel nearly half of them.