Factory speaker upgrade with no mods for 2012 package 3 with nav

I had a 2007 with JBL premium sound and it sounded way better the the 2013 w/ JBL premium sound I now have. Recently upgraded the 2013 front door speakers with 6x9 JBL and it helped the sound considerably.

Crutchfield is about as plug and play as you'll get. They send the mounting adapters as well as wiring adapters and screws (I riveted mine in and tossed the screws) along with the speakers and include install instructions.

You may have to file / dremel the speaker mounting holes slightly to get them to fit the included adapters, depending on which speakers you get. I had to on the JBL's but it was a trivial task.

If your speakers have the "acoustic lens" on them I'd do the rear door woofers as well, and be sure to get speakers that match the factory speaker impedance. On mine, the 8 speakers system, it was 2 ohms.
Otherwise you'll lose volume.