Not necessarily a group purchase per say, but I emailed a place about a keychain. They have the hatchback style-and I ordered one, but no notch/coupe. They have the patterns but not enough buyers to make a production run. Link below. I have both a hatch and a coupe so having a keychain for each one would be nice. Says they need 10 to make a run. I might be in for a couple.
I'm told that if you hit contact, then ask about the coupe keychains, once they get enough requests they'll make a production run.