I remember reading a fakes leak script for ROTF before the movie came out. At the end of the script optimus died, and all the autobots scanned beat down cars to hide from the cons. Ive started noticing similarities between this leaked rotf scripts and tf3. Its got me thinking maybe they borrowed some elements from that leaked script. The script had hot rod as an exotic sports car, ultr magnus, and I believe it even had mikaela dying. Heres what I think- At the very end Optimus dies defeating the cons. Hot Rod becomes Rodimus prime (the ferrari) and gives an epic speech about his death not being in vain.....something about the autobots staying behind and continuing to watch over the humans in disguise. All the autobots end up scanning old, rusted, easily dismissable alt modes (explains the BB datson). Than the remaining bots scatter, to hide and continue to watch over the humans in their new, more disguised alt modes.