Trademark filings have become one of the best ways for discovering the names or even shapes of future vehicles over the past few years.

So careful are automakers about protecting their intellectual property that names are often trademarked years in advance--and that appears to be the case with the latest series of Audi models whose names have come to light.

Autocar reports that several new Audi nameplates have been registered, hinting at a raft of future models. Among the names is "SQ2", which almost certainly refers to a high-performance version of Audi's upcoming small crossover model, sitting below the Q3 in the marque's lineup. The Q2 is said to be inspired by the Crosslane coupe concept, and the "SQ" designation would fit with other high-performance crossovers in the carmaker's range, like the recent SQ5.

"SQ4" has also been trademarked, so there's a lot of niche-filling coming up in Audi's future. The crossover and SUV options could expand further too as the name "Q9" has been trademarked--a vehicle likely to sit above the Q7 in the range.

Fans of Audi's e-tron electric and plug-in hybrid vehicles may also be interested to hear that "f-tron" has been trademarked. Autocar suggests this hints at a future fuel-cell car in the maker's expanding range of alt-fuel vehicles. The name "g-tron" has already been used in natural gas vehicles in Europe, so f-tron would be a logical nameplate for fuel-cell cars--such as the in-development fuel-cell Audi A7 revealed earlier this year.

_______________________________________

Follow Motor Authority on FacebookTwitter, and Google+