We’ve been bracing for this moment for the better part of four years, what with rumours and nonstop teasers building up the hype. Unfortunately for Toyota, someone over at the GR Corolla Forum has managed to find the company’s American holding page for the new GR Corolla, spoiling the surprise a day before the reveal.

This, then, is Toyota’s soon-to-be-launched über hatch, hours before you’re supposed to see it. And it looks good, doesn’t it? The Corolla Hatchback is already a fetching five-door, but slathered in Heavy Metal grey paint and hunkered down with its rally-style fender flares, it now really looks the business.

At the front, you’ll find a GR Yaris-inspired front fascia with a massive rectangular lower grille and vertical corner air inlets, along with fog lights where the brake ducts used to sit on its smaller sibling. There’s also a sizeable power bulge on the bonnet, atop which lie a pair of louvred vents, while twin holes have also been cut into the slim black grille bar up top.

Along the side, you’ll find the front fender vents shown in yesterday’s teaser, plus deep side skirts with an embossed GR-Four logo, a forged carbon fibre roof and extensions for the fat rear flares on the rear doors. But it’s at the back where the GR Corolla looks its most aggressive, with a large tailgate spoiler and a rear diffuser with a unique triple tailpipe setup – normal round tips at the corners and a big oval exhaust exit in the centre. Honda Civic Type R, eat your heart out!

Although we don’t get a clear look at the interior, a single photo shows the GR Yaris’ bucket seats, including the adjustable head rests. The reason the GR Corolla shares so many bits with the Yaris isn’t just because the two are part of the Gazoo Racing family – you’ll find an entire GR Yaris hiding underneath the bigger body.

That’s right – as previously reported, the GR Corolla will get the Yaris’ full running gear, including the G16E-GTS 1.6 litre turbocharged three-cylinder engine. Outputs have been boosted significantly to a round 300 hp and 370 Nm of torque, representing increases of more than 40 PS and 10 Nm over the Malaysian-market GR Yaris. All that gets sent through a good ol’ six-speed manual gearbox – no auto option as rumoured.

The GR-Four all-wheel-drive system has also been retained, utilising a multi-plate clutch to shuffle torque front and rear depending on the drive mode – 40:60 front-to-rear in Normal, 30:70 in Sport and 50:50 in track. Interestingly, the Corolla doesn’t get the GR Yaris Circuit Pack’s 18-inch BBS forged alloy wheels, sticking to the standard matte black multi-spoke rollers. However, buyers will be specify the kit’s Michelin Pilot Sport 4S tyres and Torsen front and rear limited-slip differentials.

So there you are, the Toyota GR Corolla. What do you think of the looks, performance and specs – especially next to the new Volkswagen Golf R and the upcoming Civic Type R? Sound off in the comments after the jump. And don’t forget to check back here for full details once the car is finally, officially revealed tomorrow morning.