Checking your balls won't find prostate issues. It's for catching testicular cancer and you should have been regularly checking them since puberty. Just give em a quick feel about once a week in the shower.
As far as prostate exams, those used to start at 40 years old but they aren't really recommended anymore unless you have a family history of prostate cancer or other risk factors. It turns out they rarely caught anything anyways.
MN requires plates on both sides and when you renew your registration they give you tabs for both sides too. It doesn't make much sense to me to require plates on both sides if you are only going to put the tabs on one side.