Warning - I had just mentioned in a different forum a few of the VAISTech issues we're run into.
1) The new XM channels (Sirius-XM actually) don't always work with the VAISTech unit. By reprogramming the unit, the channels will appear in the channel list. However, once the vehicle is powered-off, the channels don't respond and most of the time the XM switches to another channel. Sometimes the audio goes completely away. It could be the Audiovox XM tuner, but VAISTech hasn't said and it has been months.
2) Our VAISTech module died over a month ago. We took it to CarToys who had to send the module to VAISTech(!!) for repair. Over a month later we still have no module. It was under warranty at the time. So, if you want to go the VAISTech route and you have a problem, don't expect to have a repair for at least a month. I'm told maybe next week we'll get the unit back. Not a good way to keep customers...