Skoda UK has unveiled a unique Superb called the Sleeper Edition, which packs supercar levels of performance that belie its unassuming appearance. 

It is based on a range-topping Laurin & Klement 4x4 version of the outgoing Mk3 estate, but its turbocharged 2.0-litre four-pot engine has been boosted from 276bhp to a whopping 470bhp. Torque has almost doubled, from 258lb ft to 488lb ft.

The substantial increase in outputs comes from a comprehensive engine upgrade, with the regular turbocharger swapped for a larger Garrett Powermax unit mated to a bigger intercooler.

The fuel system has also been revised and the exhaust downpipe and centre section have been replaced with bespoke items.

The factory-fitted exhaust box is retained, though, ensuring that the Sleeper looks almost identical to a regular Superb Estate.

The only giveaways are the 50mm reduction in ride height – courtesy of new KW coilover suspension – and AP Racing disc brakes, complete with bright red six-pot calipers.

The Superb Sleeper is otherwise identical to the regular Superb, finished in Royal Green metallic paint and upholstered with Cognac leather. 

It has been built by RE Performance, the firm that previously modified a Skoda Octavia to hit 227mph on the Bonneville salt flats.

The Sleeper Edition is a one-off and will not be offered to the public but is instead intended to serve as a celebration of the Mk3 Superb that recently went off sale. Skoda sold 860,000 examples of the Mk3 car globally.