In each of my home theatre speakers i have 2 neo tweeters and 1 8" dayton. I can say it would sound just a little better with a 3" mid. But the 8" is fine.
Faster transient response (sounds tight) Lighter cone, lower impact in mid-bass region Ability to extend higher in the upper midrange region, therefore making two way crossover designs easier on the tweeter. Does not extend low enough in the bass region, therefore it bottoms out, and requires a bass-blocker. Weaker motors; lower SPL.
8"
Slower transient response (sounds slow) Heavier cone, higher impact in the mid-bass region Inability to extend as high in the upper midrange region, therefore making two way crossover designs difficult on the tweeter. Extends low enough in the bass region, therefore it does not bottom out, and does not require a bass-blocker. Stronger motors; higher SPL
lol im about to be doing just what you saw in your friends car. except ill be using two jl audio 6w0's. yes, their for midbass, between 90-300 or so Hz.