What Child CaR Seats Fit A Volvo XC90?

My Dad has a Volvo XC90. He took it to mothercare with my Britax Freeway Childs Seat and was told that NO car seat can be fitted in an XC 90 and ONLY ISOFIX seats can can be used in his car! Is this wrong and does anyone own an XC90 and have a regular car seat installed? I need to know if the Mothercare guy was fibbing and the name of the car seats that have been sucessfully fitted in the XC90! Thanks guys, look fwd to your responses!