Two things....
1. I personally do not choose to endorse or promote any company for free if I'm the one spending the money to manufacture the product. If I'm given a shirt at a convention or something that's one thing, but I'm not going to spend my money to promote a business that I see no return on investment from. It's a business choice and a personal one.
2. However, Rando is right. You might simply want to just ask them. It's free promotion for them and they might say yes. They might say no because they don't want there to be any confusion- meaning that they might not want people thinking your logo is a company sponsored item. They might not like the image of whatever. Personally, I think it's a very cool logo.
My 2 Lincolns,
TG