While spy shots and spy videos of new models in testing are one way to find out what a manufacturer has in the pipeline, they’re not the only way to gather information about upcoming products.

Sometimes it’s as easy as reviewing patent filings or trademark applications, and Infiniti has recently applied for trademarks on three model names that may give a glimpse into its near-future product portfolio.

First up is the G35h, which Car and Driver believes will be a G series sedan equipped with the drivetrain from the M35h hybrid. That would make for a seriously quick “green” sedan, as the bigger and heavier M35h can dash from 0-60 mph in around 5.5 seconds, while returning 27 mpg city and 32 mpg highway fuel economy.

We love the idea of a G series sedan that could run from 0-60 mph in five seconds while delivering close to 30 mpg in the city, so we’re hoping that Infiniti proceeds with development of this particular model.

The big mystery in the bunch is the G30t, since the “t” could denote either turbo or touring in Infiniti-speak. Nissan doesn’t have any 3.0-liter engines for Infiniti to use, but new engine partner Mercedes-Benz does.

If “t” stands for turbo, such an engine could be tuned to produce higher output that the G37 coupe’s current 330 horsepower, while improving fuel economy at the same time. It’s possible that the G30t could even use a large-displacement four cylinder, in which case it may potentially slot into the lineup below the G37.

Finally, the G22d clearly denotes a 2.2-liter, four-cylinder diesel, which would be the first in Infiniti’s G series range. Europe currently gets M, EX and FX diesels, while U.S. customers only get gasoline models. A diesel G would likely debut in Europe, with a (somewhat slim) chance of making it here in the future if there’s perceived demand.

It’s worth noting that a trademark filing isn’t the same thing as a product plan, so Infiniti may choose to build any of these models, all of them or none of them. Frankly, we’d love to see the G35h and the G22d in our local Infiniti showrooms.