The more appropriate question should be what is the minimum armor and armament for a car. I say Level IV plating and glass (which I supposed necessitates a V-8, so driving something like a Suburban, AMERICAN of course). As for as active threat destruction, I would say that a 40mm automatic grenade launcher+firing ports for a pair of 7.62mm machine guns. If need be, one can trade protection for firepower and roll down the windows and have the passengers shoot out of them.

I'd like to see some crappy Pukegeot or Fart or Naziwagen or Tojobishi compete with that. Although I will say one thing for French cars, they do have a really good reverse gear.

The day America sends 1,000,000 American cars to European and Japanese and Korean streets and they just bulldoze all the hamster-wheel cars out of the way will be a great day for the world.

I had a 1960 something (1966?) Morris Minor. 1000cc engine. Never started on a wet day and I couldn't do any overtaking in it. Top speed about 50 miles an hour before turning into a rattling mess. It wouldn't cut it today.

Oh, yeah, it was painted lime green 

Do do do di do... you're lovin' it.