Hi, after one of these things for my car. It should plug into the 12V port of my car, and ideally has a 3.5mm audio connector to enable me to connect my smartphone to my cars stereo unit (doesn't have bluetooth unfortunately).
Have already tried one off trademe and while it worked ok the microphone was terrible, and the use of the FM transmitter was not ideal as it had no 3.5mm audio connector.
Any suggestions? Trademe/ebay etc have a lot of these things, however this makes it hard to decide!