What exactly do you mean by hesitates?
When you're listening to the radio I would consider this situation normal. The vehicle uses two different antennas for the radio, one for when the top is open and one when it's closed. If you hear the sound cut out while listening to the radio and opening/closing the top then you're just hearing the car switching antennas. As for the CD player hesitation, I would have to hear it to know what's going on.