I am very certain that Gavirl T-series used to have two massive chunky metal air filters on both sides of the hood on the cab frame. I just realized they aren't there anymore. This accessory was in the cab section of the vehicle parts customization.
there definitely wasn't ever one in the stock game, you most likely had a mod. maybe this one? https://www.beamng.com/resources/more-parts-for-t-series.2242/