In addition to the solution video, here are the 3 star requirements in text with minimum score multipliers.
Chapter 1: Second Century - Finish under 2:30 minutes
Chapter 2: Utility Vehicle - Score 125,00 Points (25,000 points x 5)
Chapter 3: The Lotus Spirit - Finish under 1:37 minutes
Chapter 4: A Decade of Progress - Finish under 50 seconds
Chapter 5: 38mph - Finish with an speed at or above 43mph
Chapter 6: The Finest Sportscar - Finish with a speed of 205mph
Chapter 7: Aftermarket Excellence - Finish under 2:10 minutes
Chapter 8: The Art of Performance - Finish under 1:35 minutes
Chapter 9: No. 37 - Finish under 1:20 minutes
Chapter 10: Unfinished Business - Finish under 59 seconds
While obtaining the stars, other achievements related to this story should unlock towards this goal.