Was looking at my shelves and was suddenly struck by an idea. Sure enough, my "Masterpiece Roadbuster" fits inside Prime's trailer. Also, his nonposable human driver is about the same size as MP-10's Spike figurine. Since he's in an always sitting position, MP Chip Chase I think? In any case, Roadbuster came off the Cybertron Defense Force Display and went onto the Masterpiece Display. I highly recommend that anyone looking for a Roadbuster pursue this guy. There are other versions that have a more Roadbuster-y head. I just got the cheapest option. Look for CMS Mugen Calibur. Just closely look at any seller's descriptions because all three versions have VERY similar boxes.