Let me put car count into perspective by talking about 2001. I will be using the October 2001 edititon of Le Mans Series and Sportscar Racer.
--- American Le Mans Series at Laguna Seca: 2001 ---
This was obviously the edition following the 9/11 attack on America. But let's look in 2001. The ALMS raced at Laguna Seca for Round 9 of 10 on September 6th, 2001. There were 20 drivers who finished the race as 8 drivers retired. Some rounds in America included (then) ELMS competitors. This was not one of those two American races or two European races whereas the ALMS and ELMS squared off. Anyhow, 28 drivers comprised the field. Since this is 2001, the classes were LMP900, LMP675, GTS, and GT. There were 9 LMP900 entries, 3 LMP675 entries, 5 GTS entries, and 12 GT entries at Laguna Seca for this race. The GTS field was the battle between the Corvettes, Dodge Viper GTS-R models, and a lone Saleen S7R (debut race I believe). The GT battle was all German makes- Porsche vs. BMW. The LMP675 battle featured two Reynard-Lola models and a lone Nissan-powered Lola B2K/40 by KnightHawk. The LMP900 battle featured the venerable Audi R8, Cadillac LMP 01, a Judd-powered Lola B2K/10 by Intersport (Jon Field and Rick Sutherland were the driver tandem), and the unforgettable Panoz LMP-1 Roadster.
Now, let's compare that to the (then) ELMS at Vallelunga:
--- European Le Mans Series at Vallelunga: 2001 ---
This was a much different deal than in America with the ALMS. This ELMS race was Round 6 of 7 at Vallelunga and the final European leg of the championship that year. If you think the grids today in the ALMS are terrible, check this out- only 13 cars at this race on September 2, 2001. There was 1 LMP900, 1 LMP675, 2 GTS cars, and 10 GT cars. The lone LMP900 was a Panoz LMP-1 Roadster by Lanesra Racing. The lone LMP675 was a Debore LMP200 by Didier Bonnet Racing. The only GTS car was the Saleen S7R by Konrad Motorsport and RML. Every other GT car were varieties of GT Porsches and a lone Corvette C5 by Atomic Kitten Racing.
I found my November 2000 edition of Le Mans Series and Sportscar Racer and can show you what the grid was like at the 2000 Petit Le Mans. Remember that there were no two classes of prototype in 2000.
--- American Le Mans Series at Road Atlanta for Petit Le Mans: 2000 ---
The 2000 Petit Le Mans had over 39 entries because of the combination of ALMS and (then) ELMS competitors. There were 14 prototypes (no LMP900 and LMP675 nor LMP1 and LMP2 classes), 9 GTS competitors, and 16 GT competitors. The prototype battles involved the Audi R8, Panoz LMP-1 Roadster, the BMW V12 LMR, the lovely Cadillac Northstar LMP, a handful of Lolas, and a few Reynards. GTS competitors ranged from Corvette C5-R's, Porsche 911 GT2's, and the Dodge Viper GTS-R. GT competitors ranged from a variety of Porsches to BMW M3 E46's. Keep in mind that ALMS and ELMS competitors comprised the massive field of 39 cars at Petit Le Mans 2000. This was a time in which the Corvettes were picking up steam in trying to upset those Team Oreca Vipers. The 'Vettes won in GTS that year at Petit Le Mans. The highest-ranked Corvette was 9th Overall while one of the Oreca Vipers was 10th.
So why did I bring this up? I've wanted to provide a look back as to how fields were like then compared to now in the ALMS. I usually say that 24 cars is a safe number of cars. Getting about 30 per race is great. I don't know if you can field Nextel Cup-like car fields (I'm sorry I had to use a NASCAR reference in a sportscar racing discussion) for all the road courses and street courses these people run. I think a consistent count is always great. Another message board I used to participate in b:censored:ed all the time about car counts. Saying all the time that the ALMS is in trouble because of low car counts. So if car counts equal success, then is the Rolex Sportscar Series the greatest sportscar series in the world with only two classes of car competiting and insane numbers of cars competiting?
Hope I fueled something here...