Motorola V710

Does anyone have the external speaker phone that can fit into your cup holder in your car and charge the phone at the same time? If so I'm having a problem when I sometimes plug the phone in all it does is make a series of hi pitched beeps and doesn't connect properly the the speaker phone. I have to unplug it a couple times to get it working. Sometimes it works and sometimes it doesn't. If anyone else has had this problem please let me know.