http://www.mjmautoinnovations.com/Nissan that link could be helpful, will try to update how accurate it is in the next month when i replace my speakers.
Answerrear speakers are 6x9 door speakers are 5x7 the rear dash must be removed to access rear speakers also make sure the magnet of the new 6x9s isn't to big or it will get caught on your trunk springTry to use the Nissan speaker adapters plugs so you don't need to cut wires and mess up the electric system, you can get those from eBay or amazon.
The 2005 Nissan Altima has door speakers that are 6.5 inches. If you are replacing your speakers, you can also use a 5.5-inch size.
6x9
size tires for a nissan altima 2007
The front door speakers in your 1995 Nissan are four inches by six inches. The front dashboard speakers are 4.5 inches in diameter.
Answer 5 1/2 for the rear and 5 1/4 for the front.
they are 6X9 in the rear and 6 1/2 in the doors
6 1/2 in door 6x9 in rear deck
6x9 in the rear, 6 1/2 in the doors. and 3 1/2 in the dashboard
The 2004 Nissan Altima has a 2.5 L base engine size.
The 2001 Nissan Altima has a 2.4 L base engine size.
The 2010 Nissan Altima has a 2.5 L base engine size.
The 2007 Nissan Altima has a 2.5 L base engine size.