Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works well until it doesn't

This worked fine for the first month and a half. Then the charger quit working. The transmitter still works which is kind of mysterious. It was never out of the car and the device is intact and to all appearances undamaged (no loose parts or frayed wires.) I'm guessing something shorted out. It died about 2 weeks too late for me to send it back. Pretty unhappy about this since it cost $35.The transmitter part worked better than a Griffin device I had and returned around the same time; that is to say, much better job cutting out the FM signal. Alas, the charger is really kind of important so I'll have to buy another one after I do some research. The preset option is a slight hassle to mess with also when you are driving-since you can change the presets anyways, why not just add straightforward channel up and down buttons to eliminate the extra step?Be leery.