Printable View
Released on the Transformers facebook page and mirrored here for future reference are five concept art images for the TF4 movie - Crosshairs, Grimlock, Strafe, Scorn and Lockdown.
Looking at both Lockdown and Crosshairs, you can't see anything of an alt-mode on them. It's almost like, by the time we got to the fourth movie, Bay had so much more control than Hasbro, that we got generic robots instead of "robots in disguise" that have an obvious alt-mode in their body parts.
To me, it looks like the Crosshairs and Lockdown concepts are for establishing the overall look of the robot modes, possibly before the vehicles were chosen. Later on, after the cars were chosen, the models would be tweaked appropriately.
Some concept art of the Gen1 Dinobots, to see how they translate into the Movie aesthetic. They are noted as NOT being concept art for TF4 Dinobots, just a very early look at how the Dinobot concept could look, before they probably decided on using it as a plot concept.
Im digging the muted G1 dinobot colours on those - just makes me wish that the final designs featured any kind of colour on them.