The usual extra info on this series for the Ferrari F40 LM...

There are 42 events (36 Trophy + 6 TT) and the rewards 25-50-75-100% are split 9-14-19-29GC.   The LTS-winning PR76.8 gets you well beyond 75%:

The final Cup race is PR 79.3 for which you'll need upgrade pattern 5353334 costing 425GC more, but you may want to try first at PR 79.2 (i.e without Tires&Wheels 4) ...yet again the 'integer bug' didn't work for me but you may be luckier!