Just a word of caution. You might be creating a turbulence within the box where the 2 fans fight each other, with much less cooling action than what you'd assume. A bit of fan ducting could help avoid that.
If it's not supposed to be for looks/effect, a simple solution would be to spring load the "wings" and have a release button to open them. They could then be pushed in manually.
If it is indeed for effect, consider a sound generator making a noise like the sliding doors in Doom while they move