The usual extra info on this series for the McLaren Senna, plus Ariel Atom V8 and Lamborghini Aventador SVJ...

There are 51 events (48 Trophy + 3 TT) with each car having a specific two-event showcase + TT.   The rewards 25-50-75-100% are split 8-13-18-27GC, with only the Senna able to be upgraded enough to complete the series

When the Senna Track Day arrives we'll need PR 79.7 to win it, and in fact that's more than enough to reach 75% with any one of the cars (in this case the Atom):

(Don't yet know Senna upgrade costs). EDIT - upgrade does can be found here