Lid for SD Card Rack

I like AndrewZorn's minimalist [SD Card Rack](http://www.thingiverse.com/thing:64847), however it is not suitable to transport a bunch of SD cards because they are just loosely inserted in the holder. I tried modifying it such that the cards would fit with just enough friction that they would not fall out, but this proved a hassle and I'm sure that the plastic would deform over time and the cards would either fall out anyway, or I would need pliers to get them out.
Therefore I went for a simpler solution and I designed a lid that fits nicely on top of the holder. The shape of the lid reminds that the box contains SD cards.

The lid is designed such that it will fit snugly, but will easily slide off when pressed at the sides in the long direction (as shown in the needlessly fancy image that I rendered while playing with Blender's Cycles engine).