Remember the Jeep Stitch Moab concept? It conquered the Rubicon Trail this week

Concept cars usually have one job, and that's to look good on a motor show stand for a few days. 

They rarely have working mechanicals and often even lack an interior. 

Jeep's concepts are different, however, with the annual Moab collections all based on production models and therefore retaining their ability to drive. 

You might not expect them to be driven beyond the ramp of a car transporter, but they are, and Jeep designer Chris Piscitelli blew that perception out of the water by tackling one of the world's most challenging and iconic off-road tracks in the Stitch concept last week. 

Chris isn't just one of the stars of the Jeep design studio, he's a dyed in the wool Jeep guy and hot rodder. In fact, it was his idea to bring the Stitch along. 

If you don't remember Stitch from its 2013 debut, it's the second of three Moab concepts to apply the Colin Chapman philosophy of added lightness to improve performance. 

In this case, Stitch had 499kg cut out of it Swiss cheese-style with the deft application of a hole saw to the chassis, floor pan and suspension components. 

Big sections of the body were also jigsawed away, with the holes disguised by a fabric wrap. 

With just the standard 3.6-litre V6 under the bonnet, Stitch has a similar power-to-weight ratio to a 6.4-litre V8 Grand Cherokee SRT. 

Stitch's predecessor was Pork Chop in 2011, and the most recent iteration is the 4SPEED from this year's event. 

If you're thinking Stitch is alooking a little different to how you remember, it was recently given a makeover by Mr Piscitelli as the fabric covering the body hadn't aged well. 

The new Stitch is wearing matte silver paint and mesh instead of fabric, and has also scored a new set of wheels. 

Back to the Rubicon, Chris emerged after doing the 19km McKinney Rd to Rubicon Springs stretch of the California trail in either direction with a huge grin on his face and Stitch looking as good as ever. 

Jeep designers and concepts are the real deal.

What concept would you like to put through its paces as the designer intended? Tell us in the comments.