On a Nissan site I found a Silverguard Plus car cover for the Leaf, $160 dealer net cost, $230 MSRP.
These covers are made by CoverKing, which sells them as "Custom Car Cover Silverguard":
http://www.carcoverplanet.com/2011-nissan-leaf_silverguard-car-cover_ns7558.html
$164 free shipping no...