Am I'm the one to notice how Bumblebee, Bugatti, Corvette, and Optimus are always together? The Pagani and Lamborghini where their too, but they are never together on set!
I think if those two are cons so's the freightliner. The old truck? Probably Optimus in an old shabby alt mode along with Bee in his 67 Camaro mode (I only say this because of the flames on the doors). As for the Sonic... could be his part's done before the big end battle, though they're usually all present for it, or something happens to to him during the film.
But we were told earlier this year that the Aventador is in fact an Autobot.... Though I am taking any information with a grain of salt.
Were we? Don't think anything was officially announced apart from the Corvette and Bugatti being new Autobots and the three named bots.
At this point, I don't think the Sonic is a Transformer, I don't see him with the rest of the Autobots.
There is another car under a tarp there. There is a pic on instagram of 4 cars under the tarps. I'm pretty sure it's the lambo