Day on Suzuka. Definitely not possible with R$ only upgraded. Recommended PR is 54.9. 

Goal 1 - 2 lap cup on GP circuit. With R$ only, couldn't catch top 3
Goal 2 - 4 lap cup on east circuit. Again with R$ only upgrades, couldn't catch top 3. Able get average speed requirement, but only hit 273kph for top speed
Goal 3 - 3 lap H2H on GP circuit. Didn't see Magnus' distance marker until like halfway in first lap. 700m lead at that time. By the finish line, he was over 1000m ahead
Goal 4 - hunter on west circuit. Target was 400m. Only got 175m
Goal 5 - 6 lap cup on GP circuit. 

Reward $35,000/15 gold

Time to let my stage 3 R$ upgrades to cook before trying again

edit

With 17 upgrades, I still had problem catching Magnus and Zoe in goal 1.  Did cheaper gold stage 3 upgrade.  With 19 upgrades, day went without any issues.  But I'd believe the event could have been done with only 15 upgrades.

For the hunter, the 90 second timer starts when the chase car starts.  So by the time you can go, you lose 12 seconds.  I was able to finish the race in 78 seconds.  But if you do find you're just falling short, race once and then retry.  You'll gain a few seconds since the race starts at the Go green lights instead of the count down ready set go lights.