Bimmerfest - BMW Forums

so i was looking to buy black bmw center caps for my wheels, i went to pry a cap off and the back broke while i was trying to find the size.. the size was not on the cap and i have no idea what size they are. i know they are bigger than the factory ones because i tryed one from the 750s wheels but other than that... i have no idea if there is a universal size for aftermarket wheels or what? right now i have only 3 caps... i dont really mind because i was looking to buy new ones but have no idea what size. also the trunk roundel is size 82 on a 745 correct?? im opting for the more all black ones over the carbon fiber ones i have on currently.