An Infiniti spokesperson tells us the notion of an M coupe is “so far off the charts, it’s incredible.” The tease, released earlier this week during the official drive program for the 2011 QX sport utility, does tease two “product extensions” that will be launched at Pebble -- one designed to be a “volume-oriented” luxury vehicle; the other a “performance-oriented” offering.

Our source also offered that “it’s fairly obvious” what the sketch previews. In fact, after lining up the brush strokes to profile shots of Infiniti’s passenger car lineup, we’re fairly certain both vehicles are based off the G sedan and coupe.

Hot on the heels of the recent revelation that Infiniti is working on a duo of new G-based vehicles slated to debut at this year's Pebble Beach extravaganza, we've come across a trademark filing by Nissan North America for "IPL." What's IPL you ask? Infiniti Performance Line, a new catalog of in-house developed upgrades which – according to the filing – will include everything from air filters to cat-back exhaust systems, and – more intriguingly – "automotive engine parts, namely turbochargers and superchargers."