What are you playing?

Bit late to mention it to you, but in mario kart 8 there's no reason to 3 star lower ranks.
If you complete a higher ranked tournament, whatever rank you get carries on for any lower grade tournaments. So you only really need to 3 star mirror (and possibly 150cc).

At least, my ranks from playing 100cc had already appeared when I looked at starting to do 50cc.

Huh, I read about that, but people were saying it wasn't true and everything was considered separate. That would have been nice in saving some rage against the 150cc cups lol.