First, let's start with a few of the (possible) new car additions seen on set in Michigan. An alleged silver 2014 Cadillac concept car was seen and some blogs are thinking it could be a return of Sideswipe but the Autobot was actually a Chevy Corvette in the previous film.
Next, is a bright yellow Saleen S7 and in the background you can see a silver Fiat next to what looks like Bumblebee's Camaro but then next to him is a blue Mustang, too. The Saleen, Fiat and Mustang all could be new additions, or maybe all just coincidence.
Finally, Wahlberg was seen on set piloting what looks to be a spaceship very similar, or a modified version, of those cruisers seen in Transformers: Dark of the Moon during the Battle of Chicago. Below is a screenshot from the (shaky) fan video—which can bee seen in full by clicking right here—and below that set photo is an image of one of the ships seen in Dark of the Moon, for a comparison.
Transformers 4 releases in theaters on June 27, 2014.