since your car is red its best to keep out of the sun as much as possible because of the angle of refraction of the color red, usually you want to stay away from colors that are in the first part of the color spectrum (ROY-G-BIV) like red orange and yellow. My car is yellow and i park it anywhere possible sun-shade it doesn't matter(but i think the first owner before me kept the car garaged), i guess you could always just wash ur car with a high pressure hose when u get home. I don't know about nissan's paint but i know that GM's red sucks sh!t, theres this pink T.A. here where i live that used to be red, it just faded after time and turned pink. thats just sumthing to think about.
