And if you think that sounds good, try changing the front 5X7s to a component speaker system with a 5.25" woofer and a 1.75" tweeter. HUGE improvement in sound quality.
But virtually anything will sound better than the cheap Chinese paper speakers that Ford uses. Ford should be ashamed of themselves for using such a cheap and crappy sound system. Even my old 98 Honda Civic had a better base model stereo than the Mustang.