Just saw this thread. I wish I could draw as well as even that.
One criticism I have (aren't we all critics?) is it looks too much like a Honda Accord from the headlights...

Otherwise I like that you used the current model's side view mirror, and front grill/bumper cues and ridge line running down the doors.
I actually don't quite like the 07-09 Altima headlights - too generic looking in terms of the outline/shape. The '10 refresh in the Coupe version looks much better, but it still lacks the aggressive angular lines I like, the way they redid them on the '05 refresh compared to the '02-'04 (instead of the smooth curve it had on the top->inside)