What do you think of cars running on salt water?

here's my thought, global warming is inevitable, we cannot reverse the effects and more than likely the ice caps will continue melting further flooding the world. my suggestion is that we convert cars to running on salt water from the ocean, keeping the planet from flooding until we no longer need to worry about the floods. Then we'll convert to running on air or just plain water. What are your thoughts? oh and please don't add stupid comments like, do you know how much that would cost or how do you think that's possible, etc. it's just an idea ppl get over the judgemental idiocy!!!