I think I've seen this illustration of an Autobot convoy in one of the Big Looker storybooks, minus Buster and Swoop. I think this is why Optimus Prime is in the convoy, whereas he's not supposed to be present in the story (on page 52).
Sunstreaker and Cliffjumper tend to look more like a 1969-70 Dodge Charger Daytona or Plymouth Roadrunner Superbird than like the Porsche 924 and Lamborghini Countach they turn into.
Hm, there are some *similar* images in "The Great Car Rally," but nothing that looks like it was actually related to this one.
Aaaaand now I need all the Big Looker books. Thanks, Cybertronian!