However, the eligibility of the GTR was the subject of controversy, with some rival teams believing that the GTR was an in-house prototype vehicle rather than a production model available for purchase by the general public. The ALMS homologation rules for 2001 required the M3 GTR road car to be sold on at least two continents within twelve months of the rules being issued, which BMW claimed to fulfill by stating that 10 GTR road cars were available for sale. The ALMS rules were altered for 2002, now requiring that 100 cars and 1,000 engines must be built for a car to qualify without penalties. The GTR road car was never intended for production on this scale, so BMW withdrew the GTR from competition at this point.