I have been working on upgrading the stereo in my truck, 08 Toyota Tundra. I originally just wanted to add a subwoofer to the OEM stereo but carried away and now replacing just about everything from OEM to aftermarket. I have the basic OEM stereo in my truck, Toyota did have an upgraded system as an option when new.

The stock speakers are plastic framed, and paper coned. My old (1997) stock OEM Ford stuff felt/seemed better.

Im adding a Pioneer CD/DVD Headunit. JL Audio 5 channel amp. Polk Audio MM series speaking in the doors. Later getting the JL Audio subwoofer (after the credit card recovers). And of course the needed wiring. Toyota also required adapter plates to convert odd sizes and spacing to work with the aftermarket.

Attached a comparison pic.