Hi Dan,
I speak from second-hand experience. My sister who never goes to The Park, drove through it a few years back.
It was in early fall, just when there are some colours starting to show. Spying a hiking trail, She pulled over and spent the next hour or so, being amazed by both the surrounding beauty and the silence. Anyhoo, she didn't know any better/read the notice at the trailhead, requiring a permit..and lo and behold...there was a ticket on her windscreen when she returned.
For a daily vehicle permit, I think it is $13.85
hope the sun shines for ya, have a great one

Markus
Etobicoke, Onterry-airy-airy-Ohhh!