Volkswagen has confirmed the model is an extreme version of the Golf R hatchback. Its main upgrade is a significant power boost, taking power up to 395bhp.
The four-wheel drive Golf R 400 can reach 62mph in just 3.9 seconds, over a second faster than the standard Golf R, and has a top speed of 174mph.
The car is expected to use the same turbocharged 2.0-litre four-cylinder petrol engine as the Golf R, though with significant tuning and the addition of an electro-mechanical Haldex multi-plate clutch. VW says the Golf R 400 will come with a DSG transmission.
As well as its performance enhancements, VW has also added new body and bumper elements as well as flared wheelarches – a nod to the 1988 Rallye Golf G60, says the firm – new alloy wheels and an upgraded interior which features motorsport-grade seats and head restraints.
The R 400 is painted with special silver metallic paint with contrasting yellow stripes, which are echoed in the interior stitching. The R 400 is the most potent version of the Mk7 Golf since the V6-powered Vision GTI concept.
VW insiders have previously told Autocar the new model could weigh as little as 1400kg, thanks to the use of carbonfibre body panels and its stripped-out interior.
Volkswagen says the Golf R 400 is purely a concept car at this stage, with no plans to put it into production.