Have a look at this - it's in Swedish but if you waz forward to 9 mins you get a look in the Volvo Police Car factory.
https://www.youtube.com/watch?v=oPOSbBXeWuQ
Volvo took their Police cars seriously and used to market them separately, they used to add extra wiring etc to make fitting them out easier.
With regard to the speed limits, I have in my head that early XC90 and XC70 were limited to 120 mph regardless of engine.