i have an 02 chevy trailblazer ltz with the 6 disc bose hu and an over head dvd player. i was wondering is there anyway for me to play the sound from the dvd player (or aux located on same unit) through the cars speakers rather then just through headphones and the headphone jacks? there is a button on the radio that says "cd/aux" but when i push it, it only goes to cd.