i HAVE A 95 AND MINE ARE 5 X 7 BUT I PUT 6 X 8 AND THEY FIT FINE AND SOUND SO MUCH BETTER...SO ITS WORTH IT CHECK IT OUT .... OH CRUCHFIELD SAYS THAT IN THE BACK THE SPEAKERS ARE 5 1/4 BUT THEY ARE 6 1/2 SO BE CAREFUL WHAT IT SAYS.
The altimas have about 3 diff stereo options depending on the model , gxe , gle , se , ect. Speaker sizes will vary from model to model , you should visually check before buy ing speakers !