Installing a set of speakers in my Nissan Altima?

I have a 2005 Nissan Altima 2.5S model. Now the front doors have 6.5 inch round factory speakers installed. Now, the back doors don't have speakers but have an opening to install speakers. If anybody has an altima without the bose system then you know what the openings appear like. If anybody knows, is it possible to install speakers in these openings? Thanks.

ok I am telling you this cuz I did it to my car I have an 02 altima 2.5s wich is exactly like yours its just the year that changes you may be able to put speakers in the back doors but see they wont be able to fit in the hole that's in the door cuz the door panel has a groove so when you put the speaker grill it wont go down right so heres what you do the door it self has another hole right beside it but it has like a bubble on it pull that out mesurte a whole cut it and drill the speaker and grill on to the door panel then all you do is put the panel back on the door you also are going to have to run wire so you may be able to plug it into the stereo cuz there isn't any on the door it sounds kind of complex but this is the way that works best unless you want to purchase a door panel from the dealer, then it could just be a plug and play but you're still going to have to run wire for the speakers also if you're able to get a shop to fill in the gap with a molding for the grill then you may be able to put it in the original spot well how ever you want to do it's up to you I just wanted to get you something to think about well good luck

You can install speakers anywhere if you know what you are doing, but odds are if there's an opening there and there are wires you may be able to do it easily just by plug and play.

Agree that you may put speakers anywhere, but be cautious not to run the mounting screws through the wiring harness like a friend of mine did.