BMW's Area 51 [video]
BMW has a special facility, where the company tests there cars. It is exclusively available only to its own engineers. The location is not even accessible by public road. It is somewhere in Miramas in the south of France.
However, BMW has invited invite a few selected M customers, who had the opportunity to come in and do a few laps in their own vehicles or with the several M-powered cars on hand, including the M3 GTS and the M3 GT4.
The facility is BMW's own Area 51.