What's wrong with my mix? (Hardcore) (All real instruments) (Get your 2step on)

It's ironic, the snare is a multipe sampled that we recorded with the drummers snare and I still can't get it to fit ><. I'll keep working on that. I am listening to the mix in all of the bands cars, for some reason my mixes always have a really separated high end and low end with no mids, yet on my system it sounds completely balanced with mids. I'm hoping some of you guys with some better listening environments can chime in. Thanks for the advice!
 
KRK Rokit 5's, pieces of shit. Our cars don't have good speakers without a doubt, but when we listen to other albums in them they don't have the same harsh/hollow qualities as my mixes do.
 
Harsh Frequencies...hmm. Check the 1-3kHz range. Cymbals sound good.
 
Snare is a bit high-tuned for my liking, maybe tune it down a few cents and boost 200Hz/cut 200Hz from some other instruments. Good mix otherwise.