water proof seats

I have seen many aftermarket shops install a fabric ( mostly in boats ) that actually " wets " the fabric and refuses to allow water to get into the fabric as well as the cushion underneath, this would be a great idea not only on convertible models but regular cars as well simply because people very often forget to roll up their windows and should a rain shower Passover the result is a wet seat as well as door controls that may no longer function, this would be a great idea because it would impair body fluids 9 sweat ) from getting into the cushion underneath as well, what do you think, can it be done ?