U could cut the BATMAN symbol on the front panel (below FDD slot) and cover it with transparent glass and have some red LEDs from inside to project it.
Next u could cut a big circular window on the side panel, cover it with clear plexiglass. Then stick a big BATMAN symbol (sticker- all black) on it. Illumunate the inside with Yellow LEDs, it would seem like the light that is used to call BATMAN. Also u could try make the side window like the light thingy that is used to call BATMAN. For more darker appeal, on top of the window put a fine mesh of net (available in local hardware shop and made of alumunium) and don't forget to color the mesh black.
Fit a 120mm fan in the centre of the sticker, on the side panel. So basically, cut the side window, take a glass of appropriate size, cut the glass in the centre for the fan and its screws and do the decoration stuff.
You had said to suggest something in BATMAN's line.