In Bahrain, certain of the official teams run with Chev Lumina badging for obvious reasons. Holden and HSV actually have a lot of recognition - some Arab enthusiasts - guess what? - swap out the Chev badges for Holden lions! Like some GTO guys converted their cars back to 'Monaros' - the only LHD Monaros in the world apart from the one presented to Peter Hanenberger when he retired back to Germany. (M-E Chevs were sold as Chev Lumina Coupes I think).
In China, some of the official team cars run Buick badging in cross-promotion of the somewhat similar-looking Park Avenue:
It only makes sense. Now that the Commodore is scheduled to return as a Chevrolet SS, if they make it to Texas, guess why you'll see Supercar V8s with bowties (that, and the Caprice PPV)?
V8 Supercars is owned by the major teams - which means by Ford and Holden largely. They take cross-promotion to a new cut-throat level. Because Holden is into E85 with Coskata, the official fuel changed from Shell Ultimate 96 to E85 in 2009 - sponsored by Commenwealth Sugar Refineries!
If Ford has a special promotion, or Holden has a special promotion even if there's no value to the other brand, you will see the whole series change because they both know the intrinsic value to them. It's a great example of co-operation because everyone involved wants it to succeed.