In a new series of posts from Nelson, the webmaster for MichaelBay.com, more info on the Mercedes Benz E550 Autobot and another name for the Nascar vehicles has been rejected. One theory for the Benz is he is the replacement alt mode for Jolt. Not unreasonable considering the similar color scheme and shape.
Nelson posts the "Mercedes is not Jolt." He does indicate if Jolt is or is not in the movie so that remains unknown. He then later eleborates, "the blue Mercedes and the Einstein-looking bot are the same" confirming the suspicions of some. Sadly, "Einstein" remains nameless, with Nelson previously rejecting Kup and Perceptor as names. The current contender now seems to be Wheeljack. Thanks to Chris for the links.
While posting about the Benz, he also went ahead and quickly rejected another name about the Nascar vehicles. Previously guesses included Stunticons and Omnibots and now Nelson adds Rallybots to the rejection pile with a simple post of "No." to the idea.
The new theory, and maybe the best one yet, comes from an extra set report, who reportedly heard that TF3 production crew called them the "Wreckers" (now confirmed, see update below). Of all the names, I could see this one speaking to Bay the most simply due to his love of causing mass destruction. It also fits for their look with all the artillery. The Wreckers was created specifically for the comics by Simon Furman as an Autobot commando unit comprised of various and changing G1 characters. The IDW series, The Last Stand of the Wreckers is the most recent use of the team in comic continuity. Image and link from TFW2005.
Update: More from Nelson this time on the TFW2005 forums. He verified that the name of the Nascar cars with the post "They're Wreckers." He then followed that up with, "That's what they're referred to as on the set," confirming the set report on that regard. Last, he made a correction (with pic) on the model of the Mercedes Benz as an E550, not E350 as I had guess incorrectly as the number from pictures. Still not sure of the year but assume 2011. The cheat sheet has been updated accordingly.