Instruct: Classify Amazon reviews into positive or negative sentiment
Query: charges, but gets hot and interferes with FM transmitter

I purchased this car charger for my road trip from Seattle to Dallas. The charger does charge the Zen. No problem there, though the charger does get hotter than I would like it to.My main gripe is when I am charging my Zen while using my FM transmitter. You end up getting awful interference, ear piercing. It was so bad I would only charge my Zen when stopping to take a break from driving or when getting something to eat. Basically defeats the purpose of using it while on a long road trip.