Thank you very much. He is shown to have some limited version of Celty's shadow powers but mostly to change shape, and for better road handling. There's also a drawn carriage that appears a couple times in season 2 for passengers. Based on mythology it's a part of him the same way the motorcycle is.

I'm not trying to push things or anything, just giving you guys a heads up in case it comes up or if you want to adjust the cost.