I tried a one hour oval with this method and it works. Then tried a 14 hour oval and that works too. So i got money, mileage and XP. (Gr.3 vs Gr.1)
Edit: tried 90 minutes oval with the N100 Mazda and the other car Gr.1 and no joy. Only mileage and nothing else. Now trying the same thing with a Gr.4 vs the Gr.1 car on oval, will report back.
Edit 2: Gr.1,Gr.3 and Gr.4 vs Gr.1 works and you'll get everything. N100 doesn't work and I'll try N200 and above later on.
Edit 3: everything but the N100 works.