I just added an 05 Altima to my garage as well. Great car. The VERY first thing I did was remove all emblems/badges from the back of the car. It looks soo much better without them. Just use a hair dryer, goo gone, and then wax it.
I want to take that Nissan emblem and put it on a hamburger bun and take a picture.
It's an automatic but from what I understand from a very quick glance through the book, it is designed to also be manually shifted. I've not taken the time to check further into that though as my 'stang is my true love.
New grill and headlight lids are soon to come too. I like a smooth, clean look and want to get rid of the stock grill. It looks like a hamburger on a bbq grill. lol