Mine do the same thing. It's like when I first turn the car on they work for like 2 minutes then they just to the back. On the way to school today they cut out like 25 times in a row during a song. It was wierd.....Like half the time the song was playing up front then the other half was played in the back of and on. Another wierd thing that I've noted is sometimes the fronts will work when I like, push a window switch or hit my knee on the door, or even when tapping the brakes( learned this one from bumper to bumper traffic). I guess it's a bad ground or something???? Maybe a loose connector?