Only companies/individuals who have received cease and desist letters regarding unlicensed use of the MINI logo can answer that question. Not one of the T-shirt companies I've contacted is willing to risk making the T-shirt I designed without some kind of official letter from MINI that the use of their logo has been approved.
I've been considering writing MINI's brand new CEO, Stefanie Wurst, to ask her where to send my money and how much to send to obtain a license for a single T-shirt. I should get on the stick because after the 2,000-lb Chinese electric MINI Cooper arrives with 600-mile range, my T-shirt won't make sense anymore.