The Detroit Free Press is reporting that starting January 1st, you’ll be better off buying the recreation passport when you renew your tags, rather than just grabbing one when you get to the state park or state-managed boat launch.

When you add the passport to your tag renewal, it costs $11.  If you wait to buy the recreation passport until you’re at a state-managed location, the cost will be $16.
The passports are good at any outdoor site the state manages, such as hiking trails, state parks, boat launches or historical sites. Well worth saying yes when renewing your tags.

source: Detroit Free Press