[Greysard]

I don't have an iPhone, but from what I know you will need a lot of effort to connect the audio output of a smartphone to the car speakers. It is possible, but to me it would mean soldering.

I suggest that you buy a self-contained Bluetooth speakerphone for car - say, one of BlueAnt's products. I have an S4 from them, and it works pretty good. Nothing to solder :-) You don't even need to plug it in, as it has a battery inside, but I do. The battery will then charge automatically. You can also talk to it - and it works well for me.

The car's speakers won't be used (without soldering :-) but you can be up and running in minutes.

[Nifster]

sit down before you hurt yourself

[P-Marlowe]

I agree. Blue Ant is great. I used one for years, then bought a new truck that had built in Bluetooth. The Blue Ant is actually more reliable.