Did you lease or buy? If you bought did you finance with NMAC?
I'm not in Illinois but I had a similar problem with my leased LEAF. After some calling around and a trip to the Colorado DMV to get a one-month temporary registration extension I learned that NMAC had rejected the lease due to a computational error by the dealer - when that got fixed the dealer made the same error with the state and had to refile with the correct amount of taxes.
It had nothing to do with it being electric and everything to do with dealer error. I'd call the dealer and complain. If they think you'll complain to NissanUSA they'll usually take action.
Red Leaf: 2012 SL, lease, acquired 21 November 2012
Blue Leaf: 2011 SL, purchase (new, was dealer demo), acquired 4 March 2013