One of my biggest concern. The sponsors as we know divided into two and have their own deals affecting one manager's finance. One thing i notice is by progressing league races for instance finishing fourth. The next race comes up will require you to finish the same or higher. Eventually, that does mean if you win the next time you must win again and if not, no sponsor money given. Meanwhile you have things to pay off. Cars, wages, salaries etc.
I got the idea of the new sponsorhip system just within the case. The primary sponsor will remain the same, giving you race tokens. The addition is the bonus deal is given by completing the sponsor objective. For example like finish 4th or above on the season, get a total of 5 wins througout season and so on. For the secondary sponsor i will suggest actual ammount of cash as default. Bonus is handed out by objective on each races which increases or decreases based on your race performance, but if objective missed you still get the base salary offered by the sponsor. So you may not get irrritated by missing those cash because of your race finish missed its goal...