You wanted a proper, fire breathing Subaru BRZ STI? You got one. Only there's one slight problem: it's only a one-off concept.

Unveiled at the New York Motor Show today, Subaru announced that this 'STI Performance Concept' is a marketing tool to better acquaint the United States of America with the fabled Japanese tuning brand, a brand that kicked off way back in 1988.

And it's some tool. It's a BRZ, obviously, here treated to lower, stiffer STI-spec suspension, new 18-inch alloy wheels, custom Brembo discs and pads, a monster rear wing, a new aero package (new front and rear bumpers, carbon fibre mirrors and side skirts), chassis fasteners - to better control body roll - a flexible tower strut bar designed by STI, and a whopping great engine.

Out goes the road-going BRZ's 2.0-litre boxer engine, and in comes the EJ20 2.0-litre single-scroll turbo boxer from Subaru's monster GT300 car that races in Japan. Yep, it's a fully fledged racing engine.

Subaru officially quotes power at 345bhp and 332lb ft of torque, but Subaru's Dominik Infante told TG.com the concept car actually produces closer to 450bhp. "They quote it lower on the stand, but that's just an agreement between the Japanese manufacturers," he smiles. "In the race series they downgrade their power, but in reality - in this concept car - that engine makes 450."

There's no word on a weight figure, but that engine is matched up to a stronger six-speed gearbox driving the rear wheels, naturally.

Inside, there are unique gauges, Recaro seats, an Alcantara steering wheel, and a new centre stack. The new bodywork, meanwhile, has been thoroughly wind-tunnel tested, so ought to keep you aerodynamically welded to your local track of choice.There's also a custom matt blue paint job, which looks might fine to our eyes.

"In the US people don't really know who STI are," explains Dominik. We suspect after this, they just might.

Here's the bad news, though: it's not a pre-production model likely to appear at any time soon, at least according to Subaru. Speaking to TopGear.com, Subaru USA President Tom Doll confirmed: "We're still a little way off. We have to do lots more engineering and testing."

Subaru's Michael McCale was even more adamant: "This is not a production car, and we do not intend to bring it to market," he told TG.com. Boo.

However, Infante offers some hope. "If it is made, I would assume it would come to the UK, it would be easier because it's already right-hand-drive," he says.

Fancy a 450bhp, fire-breathing BRZ? Of course you do. Form an orderly queue.