Car Bluetooth Audio

Just bought a 2006 Lexus is250. I would like to stream music from my phone via Bluetooth rather than using an auxiliary cord but I don’t want to buy a new stereo deck that supports Bluetooth. Was wondering if anyone knows of a cheaper way or a device that’ll allow me to stream music on my iPhone to my car speakers. Thanks

I have a Bluetooth adaptor that plugs into the lighter. I use it daily, and it works great. My cd player is just collecting dust now.