He doesn't own the trademark hondaswap.com....
There's no judge out there who would asess damages because you had your own shirt made (as long as you don't sell them.) And that's given that B wins the lotto to cover the court costs, because he'd first have to explain what IP he actually does own in this case.
Sorry, but hondaswap.com on a t-shirt isn't going to be any cooler than anyone else who has mygenesisgetsmelaid.com on their t-shirt, if it was, a few of us would already have them.