I decided to do something different with the grill on my 2012 Volt. It cost more than I am willing to admit, because I had to buy a "used Volt grill" from a wrecked Volt off of Ebay, in order to use it as a pattern for black reflective 3M material. The old grill was scanned and then run through a computer at a local sign shop.
In the daytime, instead of having an all silver grill, I now have what looks like a traditional grill on a "regular car". Here is a link to what it looks like at night... http://www.flickr.com/photos/southwestusa/7659890598/
And this link shows what it looks like in the daytime
At night, the grill has a soft reflective glow about it much like a reflective license plate, and on my solid black Volt, I'm hoping it affords a little more visibility at night, should I have to park on the side of a road.
It's not so bright as to be overwhelming to an oncoming motorist, but I think it works for what I intended it to do and it adds just a slight different appearance to my Volt.
I'd post this photo on this forum, but I've not had much luck in getting photos to upload, and on Flickr, they can be enlarged easily.
I suppose if anyone wanted to add reflective graphics like this, I can put you into contact with the sign shop that did this for me. Their labor was VERY expensive and I'd suggest just buying the cut-pattern and applying the stuff yourself.