Sometimes you're just wandering around the web, and you stumble across something interesting. That's exactly what happened today as we were looking around at Infiniti's site. If you enter the main English-language portal page, you're greeted with this teaser image. We're not sure what it is, but we have some ideas.

The windshield angle and front half of the roofline look distinctly like the new Nissan 370Z. But the front fender flare, the fold before the A-pillar, the high-mounted side mirror and the extended rear add up to something else entirely. The front-end treatment looks a bit like the new M sedan's, though it's more intricate and conceptual than what you typically see on a production car--in fact, it's very close to that found on the Essence concept.

But the windshield angle, roofline, and shorter hood don't match with the Essence at all, not to mention the presence of side mirrors, which were done away with completely on the Essence. That leaves us with a small window in which to make an educated guess.

Given the longer roofline, the Infiniti G/Nissan Z-like overall proportions and the clearly Essence-inspired elements, we see three possibilities: an all-new G coupe, an M coupe, or a new four-door coupe. The current G coupe was updated heavily for 2008, effectively getting some of the 370Z's upgrades early, but it didn't get the more radical design of the Z, and the familial resemblance is minimal.

Working against the G: Infiniti has already previewed the 2011 models, so this would be a concept for a 2012 model at best. The M coupe is perhaps even more likely, since the M is a new vehicle to the range, and a coupe would offer competition to the German and American competition in the large-premium segment.

As for a four-door coupe, that's been speculated upon before, alongside the true M coupe, but plans from within Infiniti aren't leaking yet, and Pebble Beach is just around the corner, so it looks like we'll just have to wait and see.

What do you think it is? Let us know in the comments below.

[Infiniti]