I suspect that BMW will have to defend the claim. Although no legal precedence is set, a win by you will spread like wildfire and everyone suffering the same problems on this forum will be encouraged to do the same thing plus anyone else who has heard of it - and that will include chancers.
Have you been to small claims court before? BMW will have their lawyers there and, if it's the same as in Scotland, you get to make a statement but you don't get to add things you forgot about later and you may not get the chance to rebut anything they say.
Anything BMW or their agent has put in writing which is stupid - like blaming the roads, have it with you and refer to it. Without identifying whose car it was, I would try to slip in the MIRA report - without saying it was "provisional" because it suggests that there is the potential for a manufacturing fault and I would definitely refer to the other people on the forum with the same problem to show that you are not an isolated paranoid person. - again no names unless you have permission.
Has anyone established if the defective wheels were all manufactured by the same company at similar times? You need facts to take with you, the judge will not be impressed by hearsay and "I think".
Sorry if I'm teaching you to suck eggs.