ive had the best luck with vlingo understanding me. i just coud not get nuance or google to understand a dang word i said. thats what drove me to vlingo, im glad i did because not only does it understand what im saying, it lets me decide when i want it to stop listening. the only thing i dont like is that i cant make it my default voice app on any keyboard. if i wanna use the windows 7 keyboard i have to use the google voice. i have not tried it with my bluetooth sony car stereo because the sony mic SUCKS. the bluetooth works great for a media player, and seeing as how its the only option with a car dock now (GGGGGGGGGGERRRRRRRRRR!!!!!!!!!!!) thats a good thing. in my wifes car we are stuck with her STUPID ipod. GGGGGGGGGGGGRRRRRRRRRRRR!!!!!!!!!!!!!