The usual extra info on this series, for the Ferrari 360 Modena, plus Honda NSX-R and Porsche 911 Carrera 3.8...

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 8-13-17-27GC, with only the Ferrari able to be upgraded enough to complete the series.

You can reach 75% with the NSX-R alone, fully upgraded...

...and the same also applies with just the 911 fully upgraded.  With both combined you reach 88%.

The  final three cup races, achievable only with the Ferrari, are PR41.8/43.8/45.8 - the costs of upgrading the Ferrari enough and indeed those of winning it in the LTS are as below, as usual courtesy of Paulo over on Facebook RR3 Trackside: