Please don't do this on a car you'll be driving on public roads. First off, you'll kill your nighttime visibility both for you, and others on the road. I can promise you that you're greatly increasing your chances of getting into an accident due to somebody pulling in front of you that didn't see you coming. You'll also be blocking out different parts of the light spectrum that could be useful in allowing you to see things like debris in the road.
I can also guarantee that eventually you'll receive a ticket for this, because it's highly illegal. And that's a "fix it" ticket, which means you'll need to remove it from your car and havr it inspected by an officer before you're able to pay the fine.
With the poor light output of our stock halogens, it seems crazy to me that somebody would want to block off a huge amount of the available light output for something so ricey.