I enjoyed the cover article in the January 2012 issue of CMS. It's a good overview of a unique speed event that a lot of folks are unfamiliar with, and it captures the spirit of the thing well. However, there are a fair number of errors and exaggerations, starting right from the top. Without trying to nit-pick every fine point:
No one hits 200 MPH, although the fastest Turismo Mayor cars will top 170 on long straights. Engines are limited to 6 liters (366 c.i.) and must run a single carburetor rated at no more than 600 CFM. In Turismo de Produccion, it's 5 liters (305 c.i.) and 500 CFM.
All cars must run on Pemex unleaded gas purchased from regular gas stations along the route. None of the above adds up to anything like 600 HP.
Wrecks are common, but fatalities or serious injuries are very rare. There's nothing porous about the safety rules, which is what the pre-race tech mostly focuses on.
The go-fast tech is also not particularly porous. Cars are randomly checked for minimum weight during the course of the event. Cars with podium finishes in the top classes will undergo rigorous post-race scrutineering, and the officials absolutely will disqualify you for infractions. Also, anyone in any class can file a protest against another team they suspect may be a bit too fast, and they will pump the engines and/or pull the heads on protested cars. It's $500 to file -- if you're right, you get the money back; if not, the organization keeps it (which gives them an incentive to overlook minor violations, but still...).
The cars typically do not have full racing suspensions, at least not in the sense that track racers do. The rules restrict suspension mods, and ground clearance is an issue in the transit stages. Most towns have huge speed bumps to negotiate, much of the pavement is not smooth at all, and ride quality is an issue for the endurance of the drivers and navigators.
The reason teams semi-race on the transit stages is because they have to meet a strict start time for the next speed stage or incur penalties. The only way to have time to inspect and repair the car, have a bite to eat, or just relax for a few minutes is to get there early.
You certainly cannot drive basically any car from 1950 to 1972. Both Turismo classes are limited to 1940-1954 models, the Sport classes allow nothing newer than 1965, and the Historico A, B and C classes require 1955-1965 models only. The one exception is Historico A+, which is four-cylinder 1966-1972 cars under 2 liters.
Cars are classed strictly by age and equipment, not by speed. You will not get bumped up to a faster group for going too fast. It's not at all unusual for a number of the 2 liter cars to finish near the top of the pack overall, and they stay in their original classes nonetheless.
There has been no restriction on revs or gear ratios or top speed to date. This is proposed for 2012 and only applies to the Turismo Mayor class. Several different combinations will be allowed.
Timing and scoring are by no means well organized. It's usually a disaster for at least the first few days, with no team knowing quite where they are placed, and the more they computerize it, the worse it seems to get. Somehow they do seem to get it worked out in a way that's acceptable by the end, but this is probably the top complaint most teams have with the way the event is run. One reason the nightly banquets run so late is because the officials take that long to argue out who gets that day's podiums.
--Phil