I pointed out to them that the G8 is closer to a Bonneville in nearly every dimension, and in many cases was the biggest of three. Some argued, some said it'* for both. In either case, I don't think it really works as part of a Bonneville forum or a Grand Prix forum. It literally has nothing in common with any of them besides a badge. The knowledge base for the G8 would be a seperate of people.
Grand Prixs can try to claim it, but they are just kidding themselves. If anything, GTO forums can claim it. At least its based off a redesign of the same car that way.