Hi people my series 2 rs turbo seems to be leaking water from somewhere. The problem is if you drive the car hard it i find a load of water on the gearbox and brake servo and metering head but the strange part is that i cant see the leak anywhere under the bonnet only seems to leak when car is driven hard and also if i leave the cap loose on the header tank its fine but i cant keep on driving the car with the cap loose. Heater matrix hose is dry and i have had the thermostat and gasket replaced and also the core plug. Its something on the passenger side any ideas thanks