So if an 18 wheeler can become Optimus Prime, and Optimus Prime can become the 100% cotton Transformers Optimus Costume T-Shirt then by extension you can become an 18 wheeler! I think that's how it works anyways. Well, you may need a Class A license but I don't see why not. Galvanized by the Leadership Matrix, the Transformers Optimus Costume T-Shirt will make your chest appear to be said leader of the Autobots. Now you just need to work on your Optimus impression and/or the Transforming sound effect. Either or should work really.