You’d be surprised at how big the Volvo aftermarket is. Unfortunately I don’t know any specifics about modding Volvo’s, just that there are a lot of hardcore Volvo enthusiasts. One of my old roommate’s at UB was a Volvo nut and we used to shoot the shit a little bit about boosted Volvo’s and such, that’s the only reason I even know that anyone mods Volvo’s. 
If anybody lived in Hadley last year he was the kid with the loud green 850.