This is one thing that's said a lot that the more I think about it, makes no sense. For a start, Bumblebee is a 70s Camaro. The TFs wouldn't know how common or old a vehicle is, more than likely, when they scan it. Secondly, some flatnosers are ENORMOUS. The Peterbilt isn't as big as you think. Some Australian Kenworths are just as big. Thirdly, have any of you watched Spider-man 3? Note the Truck that Sandman appears out of? What kind of Truck is that!? Not just any flat nose either, it's a Freightliner. An Optimus Prime truck! Do you really think anyone in the cinema thought "Hold on, that's an OLD truck! It must be a ROBOT IN DISGUISE!". I think long nose trucks are just too awkward to Transform. As you can see Prime's one of the more awkward designs to recreate in toy form. Flatnoses are bricks you can just take any part you like out of. Not that I don't like his current movie Truck, I've grown to really like it, but it's not the only way he can look.