I wonder how many would be all over the idea if it was Mad Max's
I say let the teams bring all the cars they want to race. If they qualify let them in. Same with limiting the number of teams why not limit grid positions. If a team can get a car in so be it. Back in the good days of Indy they would spend two weeks to qualy the cars. This would allow teams with a limited budget to slap together a car run a few grand prix and hope to get a sponsor.