My game save with all gold on S license got corrupted last month.
At the moment all gold on S apart from S6 and S8 which are silver.
It took approx 1 hour to convert silver to gold for S1, S2, S3, S4, S5 & S7. Having done all to gold level over a year ago is an advantage as you remember how to get the gold time. I however still require practice to get back to pace. S8 will test me as that took a lot of time for me to get gold last year.
If you are having trouble getting bronze watch the demo with the displays showing so that you can get an idea of corner speed, braking points, etc.