Dealer says toyota xm requires nav system installed?

I received my new green 2006 Prius last Saturday, had ordered a couple of weeks ago, but the dealer called me that someone had cancelled their order for the same package (4) last Friday, and was I interested, so I said yes. He'd ordered an XM radio through Toyota. I've been using XM using the Roady for several years, so I asked them to install the XM radio. I left the car yesterday at the dealership, and was told to check back today.

The service man spent six hours installing it, but never could get it to work He made a number of calls to Toyota trying to get it to work, and was told that it would only work with the Navigation system installed. So now, I have to leave the car another day while he removes the XM radio :<( .

Has anyone on this forum had a Toyota Factory XM radio installed in a Prius without the Nav system.

Thanks,

Stokes