When carmakers overcome their rivalries to join forces on a single vehicle, pretty strange things can happen. The entertainment world has a phrase for this phenomenon — the ever-anticipated “crossover event” — though crossovers have a different connotation in car land. So we’ll refer to these inspiring displays of teamwork as “collaborations” instead.

As we discussed last week, of its own, some celebrated, others completely forgotten. But Porsche’s hardly the only company that’s made a strange bedfellow for another carmaker, so today we’re asking you: What’s your favorite collaboration within the auto industry?

Drive free or die.

The criteria here is wide open. I don’t care why a certain union is your favorite, only that you’re passionate about it for one reason or another. Maybe it produced a beloved result, like Porsche and Audi’s work together on the . Maybe it was doomed from the start, like the . Or maybe it’s just flat-out jarring to behold, like my selection: the Toyota Cavalier.

I was so accustomed to seeing Cavaliers blending into the asphalt beneath them in my youth that the image of a Toyota badge on a car that my colleague Raphael recently called “” seems perverse. What makes it even more surreal is the ad copy. It’s clear that Toyota was gunning to sell the Cavalier to Japanese customers on a jaunty, liberating vision of American motoring — a vision that would inevitably burst the first time a prospective buyer sat inside a Cavalier. Still, the green one with the basket-weave rims actually looks pretty nice.

Enough about subpar compacts exported out of political necessity. What clash of automotive titans do you find great, terrible, or just plain weird?