FM Transmitters with Bluetooth (which version of BT):

[Crow550]

Is it best to just go with 4.0 or does it really matter if it's 3.0 or 2.1?

 

[ThisIsChrisKim]

4.0 has much better efficiency, so it'll be much less battery drain, if that's something you're concerned about.

 

[soccerballtux]

don't. bad audio fidelity

 

[Crow550]

don't. bad audio fidelity

Only other option is regular FM Transmitter which I was using. I'd like to cut down on the amount of plugging and unplugging too. Figure why not.

 

[Chocu1a]

Best sound I have found in a bluetooth fm module is the Roadster by Motorola. Using one in my suv. Works well enough, plus allows for hands free texting & call answering.