An opinionated and non-mainstream position
...according to Alex Blackwell above. Now, I am not advocating arguement by authority but I'd say that the question of substantial subsurface water on Mars is hardly proven either way. In fact, the preponderance of peer reviewed literature supports evidence for hidden water. Since the question is still open thanks to Nick's excellent alternative view, I'm waiting before adopting your iconoclastic view of Mars.
-philw