FISA Gp4 homologation required 200 units to be built. This was applied to the original HS spec cars, not the widebody HSRs. Vauxhall entered the first works HS cars with the Lotus development engine, but the street cars had the Vauxhall DOHC.
When this was discovered after a few races, they were banned until they got their act together. Big scandal. They still never made the full number of homologated cars. How they got that past FISA, considering the first bluff, is one of the all-time mysteries! Only 50 HSR 'evolution' cars were required under FISA homologation rules. Vauxhall showed FISA a few competed cars, a bunch of bodykits and intended works cars which they palmed off as street homologation cars, and bluffed their way!
In fact, many of the HSR cars (ours included) were converted to R spec from HS cars......so the same cars were homologated TWICE
The whole Vauxhall homologation bobol is legendary. To this day nobody has the official numbers, and nobody can explain how they got away with it