My car doesn’t have an auxiliary port jack, let alone a fancy USB or iPod connector. I’ve tried headphone jack-to-cassette adapters but they fail after a few months. I a tried headphone jack-to-FM transmitter but I could never keep them positioned for good reception. Both solutions required using my phone (if I could find it under the seat it slid under) for playback controls.
Finally I found a Bluetooth-to-FM transmitter that solved the issue for me. The GOgroove FlexSMART X2 connects to your media player via Bluetooth and to your car radio via a tunable FM transmitter. It has a microphone on the device so you can use it as a hands-free speakerphone. It also includes a USB port for charging your device and an line-in jack to connect a Bluetoothless device.
I purchased the model where the adapter is on a long stem because my car’s power outlet (formally the cigarette lighter socket) is near the floor. The stem brings the adapter close to the front of my radio, close enough that the radio gets a clean signal at all times. (A version of the adapter without the stem is also available.)
I’ve had the GOgroove over a year and a half now and it has been worth every penny. While I initially bought it for podcasts and music, it turns out it is great for voice over GPS navigation as well. Finally I can actually hear the instructions.
I’ve only run into a few issues, mostly during the initial setup. I had a problem with static on the FM signal when using the USB charger. I found tuning to a higher FM station mostly resolved that problem (I only use the charger on long road trips anyway).
I also had a problem with volume at different times. In general you want to turn the bluetooth volume from your device as loud as possible, then control the volume you hear with the radio volume. I found doing this I could use my normal radio volume setting. If I did switch to radio it didn’t suddenly blare because I had to turn it up for my phone.
However the iPhone seems to set all Bluetooth volumes separately and they have to be set via the Bluetooth device. I thought I had a problem with the Siri volume not working properly even though I would increase the volume on the phone. Instead I had to activate Siri, and turn the volume up via the GOgroove. I did this once and the volume level has been remembered correctly since. I had to do the same for ringtone volume as well (trickier in that I had to wait for someone to call me, then get the volume up before voicemail kicked in.)
The only ongoing issue I’ve had is that in cold conditions (< 20°F in the US Midwest) the radio doesn’t connect immediately as it does in warmer weather. I turn the GOgroove off, wait about 30 seconds, and turn it back on. It connects immediately after that. Not sure if this is a problem with my car radio, or the GOgroove, but it’s only a minor inconvenience.
My final concern was with security and privacy. I’ve not had a chance to test how far away from my car it’s possible to tune into my signal but radio waves can be weird and picked up much further away from the broadcaster than you might expect. Using the microphone on the device your side of the conversation is via encrypted bluetooth only, but any response from the other person is broadcast FM radio. If you have Siri read a text to you, it is being broadcast as well. As it is, I avoid most of the handsfree interactive stuff and just use it as a podcast/music/GPS player.