I don't have an 850 to look at, and I'm not that familiar with how the hoses are routed. However, I would suspect a split heater/radiator hose. When I broke a hose on my 240, I could see a small but steady stream of coolant dripping under the car. Perhaps you have a bad seal at the water pump and the coolant is hitting the belts and spraying it all over the engine bay? Clean the engine, find out where it's coming from, and fix it.