In my opinion class seperation should have NOTHING to do with sponsorship.
It's about skill folks!
If you're a novice driver, run Novice.
If you're a sportsman driver, run Sportsman.
If you're an expert driver, run expert.
Pro class... Well none of us are named Drake, Cavalerri or Tebo... So I doubt we have to worry about that.
Rules should state... If you've won a certain percentage of your recent entries into said class you are then required to bump up.
Say little Johnny WINS 3 out of 5 of his last races in Novice. He now has to bump to sportsman.
Say little Timmy hasn't won anything in the novice class... LET HIM STAY THERE till he is faster than the other guys in that class.
This is how the class seperation should be done... Should have ZERO to due with sponsorship.