You can finish the entire motorpass in just 22 days, if you play it smart.
Find out how fast you could finish the entire season of a motorpass here.
I was curious as to how fast i can get those 500 stars, so i made a spreadsheet to find out.
In just 22 days you can finish a 56 day long season, if you do all dailies and weeklies.
This does not consider star rewards. just assume you might finish a day or two earlier.