Although production-based cars still raced, they were now in the lower classes while purpose-built sportscars became the norm.
One-make, or single marque, championships often employ production-based cars from a single manufacturer or even a single model from a manufacturer's range.
Porsche would instead concentrate on development of the 911 GT3-R, a production-based car for various Grand Touring series.
The Spec Miata (SM) class is intended to provide the opportunity to compete in low cost, production-based cars with limited modifications, suitable for racing competition.
With the re-introduction of production-based grand tourer-style cars in 1993, Porsche saw an opportunity to exploit a loophole which existed in this new class.
WRC-3 is limited to production-based cars homologated under the R1, R2 and R3 rules.
Single marque series are often found at club level, to which the production-based cars, limited modifications, and close parity in performance are very well suited.
All this was more evidence of how difficult it had become for a production-based car to compete at the highest levels of endurance racing, especially without full factory participation.
GT4 is another new category for non-professional drivers in production-based cars with very few racing modifications - for example, no aerodynamic aids or body modifications are permitted.
WRC-2 is limited to production-based cars homologated under the Super 2000, N4, R4 and R5 rules.