White light up emblems?
 

Anyone have any idea how this could be done?

youd have to remove the emblem, cut out "Nissan" in the emblem, cut out a rectangle in the shape of the burger part of the emblem, and mount an led or two in there...

Sounds like it would look bad when seen in anything else except at night. I was thinking more of how the illuminated kick plates are made. glass/clear plastic over the emblem and led hidden from view

Lighted Badges
 

I do not know if this will help in regards to your badge question, but while checking out possible related sites, I stumbled onto E-Bay and found they offer a few badges that light up. I purchase two different ones to use on my current project. I make a choice once I receive the badges. Darkskyz2.0:driving:

I don't know how good it will look no matter what you do, but to each their own...

I think ECON's suggestion is pretty much the only option without fabricating something new.

There's a site that sells these but are pretty expensive. Stumbled upon it and never thought of putting in my favorites.