My Nissan Juke needs a new gearbox - how do I make the supplying dealer pay to replace it?

My 2012 Nissan Juke CVT has developed a transmission problem and requires a new gearbox costing £7000. The car has only done 28,000 miles and we bought from new. It has been serviced and maintained by the dealer we bought it from. What can I do to get the dealer to replace it at their expense?
You have to use Clegg v Olle Anderson, House of Lords, 2003 where the ruling was that if something was sold in a fundamentally faulty state, the supplier remained indefinitely liable. Sufficient numbers of CVTs in Juke and Qashqai are on record as having failed: www.honestjohn.co.uk/carbycar (to provide documentary evidence of this).
Answered by Honest John on

Ask Honest John