Originally Posted by Buffalo-Lax35
My other main concern is making sure that all the speakers still work with the new head unit..Does any additional hardware have to be purchased along with a new head unit to connect with the factory speakers, or is it all a pretty seamless install?
The speakers are connected to the amp. The amp is connected to the head unit (the receiver you are changing out) via a bundle of wires that leads to a white plug that goes into the head unit. Some folks call it a "harness". When you pull out the old head unit, remove the white plug and the antenna jack. When you have your new head unit, insert the white plug and antenna jack.
No need to touch the amps or speakers if you are only changing the head unit.
Some head units will require an adapter. Most reputable dealers know what our cars need connection-wise and will supply the adapter (or sell it separately).