I just bought both of these FM-Transmitter-Bluetooth devices and this will solve your problem. Also, makes a great X-mas gift:
Option #1) This transmitter also has a power off/on button; and it has a "Beats" button for two settings, which I did not evaluates, but must has some value when streaming music. I was most interested in voice clarity so I went with the transmitter #2 listed below.
Option #2) This transmitter does not have a power button, but in our FX models the cigarettes' lighter power is turned off/on with with the ignition key. So this is convenient. I.e., you don't have to remember to power down the unit when you get out of the car.
I also like that this #2 transmitter has a built in voltmeter that shows your battery-alternator output voltage for a few seconds when it first powers on. And I found this transmitter's volume control is 1 step higher then the model above. So when I'm listening to my Audible audio books I need this extra volume step, because for some reason the audible output volume is lower than my other volume functions.
Both options get high positive reviews! Just "pair" your phone's bluetooth. Then dial up an an unused FM frequency on your transmitter. (I used 99.9 FM) And then set your radio to 99.9 and enter it a preset #6... as a suggestion. Now you just press preset #6 when your phone rings. I also found both microphones to work very well and the voice clarity was very good too. I highly recommend these new generation FM transmitters. They work great and are priced in the $20 range or less.