On the new crew:
Michael has a totally new crew for this movie (aside from the DP & the AD). Stunt people & drivers, SFX crew, camera crew, and grips. I guess it goes with the whole "fresh" feel and look of TF4.
Optimus Prime's new alt mode design:
The truck company for Optimus Prime in TF 1-2-3 never wanted anything to do with the movie franchise. Before filming the first TF movie, the production crew approach the truck company to see if they could lend them 2 trucks. They said no. The producers then found 2 old rusty 1995 models that barely worked and gave them a paint job that got the job done with a very tight budget for chrome and stuff. This time around, Western Star (a subsidiary of Daimler Trucks North America) gave them 2 new trucks. No questions asked.
Optimus Prime was painted by West Coast Customs.
Ownership of the new cars:
There are 2 of every car, truck, and vehicle in this production (one for back up).
1 Bugatti is owned by a private owner. The other is a loaner from Bugatti.
1 Lamborghini Aventador was purchased by the studio. The other was purchased by Bay (the one with the interior shots in the movie).
1 vintage 1967 Camaro SS (BumbleBee) is owned by the studio, the other by Bay.
Optimus and BumbleBee GGI renders are still being tweaked. Optimus looks grand and BB looks sleek, refined and badass.
He also shared the following set images: