How to make speakers sound good outside of truck?

Before you think I'm one of those punk kids trying to annoy everyone with an overly loud sound system, please hear me out.  I hate them too.

I love camping and the outdoors, and often use my car to play music for my group of friends and I when we're camping.  I am about to purchase a 2012 Ford F150 Supercrew and would like to upgrade the sound system in the truck.  I know from experience that the sound doesn't sound super good, other than the subwoofer, when you get more than 20ish feet away from it, and would like the whole system, especially vocals, to be heard clearly even from outside the car.  How would I go about properly soundproofing the car to keep it from rattling while also making sure the sound can be heard clearly? (Assuming all the windows are down)  Is there a way to position my car speakers or a specific way to soundproof it or a specific type of speaker to get?  I would ultimately like to install a proper component sound system with a dedicated amp and 2 12" downfiring subs under the back seat.  Thanks for any and all advice!

Also, sorry if my terminology isn't exactly right, I'm still fairly new to this and have only messed with my current car's sound system a little bit.