At the end of each season, depending on where you finish, you should receive prize money with finishing 1st in elite receiving the most and finishing last in rookie the least. This would allow teams promoted to have money to improve the following season as they wouldn't have done well in races and lose money for most of their races
Great idea but the game is also there to make a profit. So if the teams get the bonus like you say then there is no need for people to spend real money on the game and keep the game going! Got to pay the guys running the game somehow.
Not to mention the fact that if such system existed in this game then current top managers would always hold an advantage over the rest of managers. The current XP point system addresses that variable quite nicely, I think.