I admire the thought, logic and philosophy behind the old story that so many centuries ago, this was thought to be impossible but now it isn't. I can see you trying to link it to this.
But this scenario is very different. In lab or at work you might not see things go by the book, sure that's life, shit happens (excuse my French). However, calling this against 'by the book' would be a massive understatement.
What the entire scientific community at large deem physically impossible, this guy from who knows where, with who knows what qualifications proves them wrong? I don't think so, maybe if I see it, I will believe it.....
Otherwise, everyone on this thread who have cast their doubts have done so with 100% validity.
Many more arguments that come to mind as to why this is fake, but we need not go into them when the basics of it tell us that from what we know, it's impossible.
Physics and engineering aren't everyone's forte.
But I do agree that the response in the media and some in the so called 'scientific community' in Pakistan do reflect on the education level.
And above all it shows just how gullible some Pakistanis are.
battery would have to be changed/charged after may be an hour or max 2 hours. This water car engineer is just a retard whose degree needs to be checked for if its real or fake. What he is saying is a lie of such obvious scale that no engineer(real one)/scientist would even listen to this man for a minute. his whole water kit sounds like a grade 8 science project of electrolysis. you can buy one on amazon for 10$ 
