Came across this thread when I was considering a plate for my IB. I originally wanted to copy my previous E36 plate (my first m3) which was 'E36 S52'. I'm personally only a fan of plates that car nuts would get... I'm not a big fan of obvious plates like "BMW M3" - lol - no duh!
My current plate and previous BMW plates I've had. A little piece of my previous M cars is carried forward each time with the exact same license plate frame lol. cheers