Autopia Road trip around VMK and license

Hi guys, I'm hoping someone can help me with this.

I was told that there are different levels to the Drive Magic pins (Easy, Medium, Etc.) but can only find -and have completed- the easy quest. How do you access the higher levels of the quest?

Also, as a side note, I'm trying to get my license but my Drive Magic doesn't last long enough for me to go around the track and collect the gas cans. Anyone else have this issue?