Reflectors and alternatives

[RandomConnections]

In the portraiture class I'm taking we got into a discussion about reflectors - silver, white, and gold. These don't seem to be too expensive (about $15 from Wolf Camera for a small one.) However, I'm wondering if anyone has tried using the twisting sun shades available for car windshields? It seems to me that these might just be reflective enough, and they are certainly cheaper.

[Saralonde]

I bought 2 of these from Target last spring, a gold one and a silver one. They were marked down to $2.25 each, so I figured I had little to lose. While I don't use them very often, they do reflect light. I don't know how they compare to professional reflectors because I have never used those. Has anyone else tried this?

[CallampaPhotography]

I was just wondering the same thing, however could those also be used to create a light tent? are they transparent enough?