SiL has just pulled up at the back of our homestead in his BMW 325i. Has has a caustic smelling blue fluid leaking from his passenger seat which wiffs a bit. Seats are heated and electric for movement. Colour of fluid leaking is blue. I'm thinking its "heated" seats related and not to worry too much as it appears all to have leaked out now. Dont half pong tho, a bit acidy. Any answers greatly appreciated.