Have replaced radios in my cars in the past but I am wondering if there any special things needed besides the basic stuff.

 

what are you looking to install in its place? the wiring is common to 850s/S70s as is the double DIN size... Easiest would be to swap in another Volvo unit with more power/features or you can search eBay or Amazon for a wiring harness converter and go after market.

 

Check Crutchfield