The TGV12 was Jeremy's car-based train that was featured in Series 17. It was made from a Jaguar XJS and an unspecified make of caravan. Jeremy, Richard, and James originally planned to all use the same train but disagreements in carriage numbers left Jeremy with the XJS. Also, Jeremy wanted to make a sports train which was fast.
In sticking with the red colour of the Jaguar XJS, Jeremy found a red caravan and, from what can be observed, cut the top off to leave it roofless. He placed four seats, all with a harness belt, at the front of the carriage and a large spoiler at the rear. He also had goggles for the passengers.
To their trains, the presenters all invited passengers on board their creations and travelled from Leicester to Loughborough. Jeremy invited the editor of Railway Express magazine and an unknown man on board his train. The editor of Railway Express subsequently provided a review of his experience on the TGV12. Throughout the trip Richard and James' train caused problems for Jeremy; the most obvious of which was the speed of Jeremy's train was considerably faster than theirs and as such the TGV12 was stuck behind for large portion of the journey. The TGV12's most immediate design fault was the fact that bugs and other flying insects constantly hit the faces of the passengers, a problem only minimally addressed by the provision of goggles. Another design fault was observed when the TGV12 was put into reverse. The bonnet of the Jaguar had to be kept up as no air was going through the radiator and the size of the carriage meant Jeremy couldn't see out of the back. Later, Jeremy nearly collided with another train after changing tracks to overtake James and Richard. He eventually reached Loughborough and the TGV12 was deemed the best after the competing train of James and Richard caught fire, and they consequently failed to reach their destination, as a passing train ran over and destroyed the last carriage.
The TGV12 was brought back to the Top Gear studio and the review from the editor of Railway Express magazine was announced and read. He said: "There was nothing to eat, the ride was awful, the noise was distressing. I spent most of the day going backwards, I genuinely feared for my life, and I ended up covered in excrement". Jeremy combated this by saying "so it's exactly like a normal train... only much cheaper!".