McNab said:Stu, Steve,
Have either of you had heavy rain in your part(s) of the world? It doesn't sound as if it's coming from above, and I wondered if you've had to drive through largish puddles or longer stretches of water.
Or could it be pressure-hosing? Got me in a panic now - will have a look in the spare wheel recess tomorrow a.m. Mine hasn't stood in the rain or even been out on a wet day, so if there's anything there it'll be the pressure hose.