Any recommendations to get hands free phone on a 2003 trailblazer ltz with original in dash 6cd radio?

It has onstar, but its too expensive for the few times I drive this vehicle. State law is mandating hands free phones, so I'm looking for options on my trailblazer.

Thanks.

 

There a devise called a fm converter maybe about $15 for it. Tune to the fm channel and they work great instead of paying hundreds to upgrade. Also amazon has a replacement for onstar module that works and use exiting system for about 115.