Jeff Gordon was interviewed on the practice show and was talking about added cautions and said something that should be taken more seriously. he said he grew up racing with heat races and main events and if they want more entertainment that they should adopt that.
And I think he's onto something. The races are generally too long, the cars are legislated to be too equal and the some fans, at some NASCAR has cultivated with lucky dogs and fake cautions and GWC finishes, seem not to have much of an attention span. NASCAR has two races are many tracks what they should try during the first half of the season, so it doesn't interrupt their Chase, is run a couple of weekends with a heat race format as a test. It could even cut down the weekend to a two day show from three as Friday they get no crowd anyway.
Have practice for a couple of hours on Saturday morning and afternoon with the support race, that sets the times for the heats and main on Sunday. You have enough heat races so by the end of the day Sunday you've had 500 miles total. And you end up with 24 cars in the main event. You have four heat races of 50 miles each and take 8 from each, then you have the B main for 100 miles, one mandatory green flag pit stop with those 32 cars to get to the 24 for a 200 mile race. That way you've had 500 miles of racing for the fans, 350 for those in the final 24 race. You pay points and money for each of the three levels, obviously more for the final. You cut down on the start and park in the heat races because teams would get more money for at least advancing to the second round so why not run through a set of tires. You save the teams some money if by only having 350 miles max of racing and the teams that don't run the final spend even less. The cream generally rises to the top and th big teams would be in the final most of the time.
The early races at Bristol, Martinsville, Dover, Michigan and Pocono would be good candidates. And if the idea takes hold they should keep Daytona, Talladega, Darlington, the Brickyard as full length races to create a series of 'majors' like golf or tennis has.
I would then throw in no pit stops under caution, and eliminate all their gimmicks. For the NASCAR way of doing things they would get to promote the heat race winners as a big deal and be yelling on FOX about the transfer spots in every heat. In person it would give a few breaks in the track time to get more people tot he concession stands. NASCAR wouldn't dare take the chance to even experiment with a couple of races to start but it could be a new take on the races.