“Sirius Satellite Radio Inc. and XM Satellite Radio Holdings Inc. said Thursday that Subaru agreed to offer their radios as options for some 2007 models.
[...]
Beginning in May, Subaru will offer Sirius exclusively in the 2007 Subaru Forester. In August, Sirius radios will be available for the 2007 Subaru Impreza, the company said.
In a separate statement, XM Satellite Radio said its radios will be offered in the 2007 Subaru Legacy and Outback, as well as the B9 Tribeca sport utility vehicle. The special edition B9 Tribeca will feature XM radio as standard equipment.”
According to XM, you will also be able to request XM Satellite Radio as a dealer-installed feature on other models, such as the Subaru WRX, in 2007.
Read more at Subaru to offer Sirius, XM radios