When I put the phone in the car dock, and have bluetooth enabled to a clip-on speakerphone thing (Motorola T505), the google voice search app doesn't detect any voice at all. Now, with the original Droid, it never used the bluetooth mic as the voice input, only used the mic on the phone, but if you got fairly close it would be OK. With the Droid X and the new car dock, it almost seems as if the mic is disabled or it's trying to use the bluetooth mic but can't so gets nothing.
On a side note, neither the Froyo Bluetooth Voice Dialer or the Voice Command thing in Droid X 2.1 can handle navigation requests ("Navigate to 123 Mockingbird Lane") like the Google Voice Search can. Very frustrating... Why couldn't they have built something on top of voice search instead of voice dialer, at least as an option (not the best, since it requires a data connection, but still it's more flexible...)
On a side note, neither the Froyo Bluetooth Voice Dialer or the Voice Command thing in Droid X 2.1 can handle navigation requests ("Navigate to 123 Mockingbird Lane") like the Google Voice Search can. Very frustrating... Why couldn't they have built something on top of voice search instead of voice dialer, at least as an option (not the best, since it requires a data connection, but still it's more flexible...)