If you keep making noise with the phone (the mic will be shut off, so keep pressing buttons or make a call and talk into the other phone), the sco link should stay active as long as you're making noise.
I wish there were some way to disable that behavior. Maybe there's an AT command to do that?
Anyways, stability is what I'm after here. Handsfree won't do me any good if I have to restart things while driving!