Audio Systems: car audio, wiring harnesses, rear speakers

Question
what size are the rear speakers of a 2002Chrysler 300M?
How do you install aftermarket speakers? Is it Hard?  

Answer
Go to:

http://www.crutchfield.com/S-2oUYx0ChoRw/app/car/mycar.aspx

where you will find complete listing of components that are compatible with your car.

Crutchfield maintains the most comprehensive listing of products for cars there is.

If you purchase from Crutchfield (and you don't have to at all to use their database) they will send the installation instructions and wiring harnesses that may be necessary with the purchase.

But, simply speaking, if you obtain compatible speakers (size, mounting dimensions and impedance are the most important) it is just a matter of pulling out the old ones and installing the new ones into the same mounting holes using the same hardware.  If the new speakers vary some you may need different hardware.

Good Luck,
Cleggsan