The best cars for the NMax20 Cup are the Akura RSX Type S (for wet and dry asphalt races) and the Lancia Delta 16V (for mud and snow races).
As more and more teams increase the capacity of their racetracks, and enter cups like the NMax20, so the potential rewards for taking part increase every season. With a registration cost of only 5000 cr, any team who has techs close to or above 20 should always enter the NMax20 if they have an eligible car.
I did fairly poorly this season in the NMax 20, but I still made 91,000 cr from spectator and rarity income, plus 25,000 cr from reward income. Thats 116,000 cr for a 5,000 cr registration cost, and I didn't even reach the semi finals. Don't look a gift horse in the mouth next season - invest in the cars and enter the NMax20!