The perfect setup for intermediate players is, I believe, the Ferrari F1 seasonal on Eifel with F10 (or F2007, prolly wouldn't make much difference) detuned to 755-760PP. With added approximately 160 kg of extra weight (353 lbs), slightly improved downforce, closer gear ratios (actual top speed while drafting: 320 kph/199 mph), brake balance changed to 10/10 and reduced horsepower I was able to beat it in 11:20.xxx trashing the 2nd bloke by 9.5 seconds. With this setup you can floor it on almost every bend but to do so, I strongly recommend turning the SRF on and TCS to 1. It's just makes things easier. The prize would be a bit more than 4 million Cr and almost 600,000 experience (200% bonus, obviously). The track is easy to learn and actually reminds me of some parts of Interlagos and Spa so, it's fun to drive there as well.
I know you can get up to 4.8 million Cr in one race but it would still need to be repeated 5 times in order to reach maximum account balance. With earning "just" 4 million it's still 5 tries, only you have much more room for error and overall, it's just less stressing.