[Tannaton]

All post 2003MY Volvo AWD models are Haldex based and therefore have no problems whatsoever with un-matched tyres - despite what many tyre outlets will tell you when trying to get you to buy a set of 4.

However, from the point of view of safer handling and predictability, you should try to match tyres across each axle and put your best set to the rear. This is documented in your owners manual.