going to start looking at replacement speakers

I was driving my truck today with both windows down (2012, regular cab).
The stereo was hard to hear with the volume turned almost all the way up, and it didn't sound too good either. I'm using a stock radio (navigation) and I don't want to add an amp.

Time to start reading some audio threads

 

good luck lol
Aftermarket speakers will end up making you lose some total volume.
Volume takes power, and the factory radio just ain’t got a lot of power unfortunately

 

Really depends all on what you want, I would start at minimum maybe upgrading your door speakers and find a decent head unit with a built in amp. $300 or so should be a decent budget, probably a little more. Generally speaking higher quality speakers will require higher wattage, that's just how it is.

You may still end up needing an amp though, they're fairly affordable to add and easy to stick under the seat... running cables isn't hard to do in our trucks with such a small cab.

You could sound deaden your entire interior and keep it stock, then go from there. Just sound deadening the back of the cab with dynamat behind the seats helped a lot for me. You'd be amazed how much sound is sucked out from road noise and the tinnyness of the cab.

The reason a lot of higher end makes have nicer sounding stereos isn't necessarily because of the speaker quality or the actual stereo, it's because there's a lot of material to pick up excess vibration.

Spend a little bit on upgrading your stereo but don't expect "audiophile" sound or whatever.