I remember hearing this before and still can't believe it. You don't need to get that close to be able to see the shutlines for the back doors even if the door handles aren't visible, and if you are specifically looking to see if it's a five door surely this would catch the eye.
Either these people that were put off weren't really that bothered about getting one in the first place (if you were that bothered you'd have surely gotten close enough to realise it was actually a 5 door) or they were too simple to at least ask the question of if a 5 door model was available.
As you can probably tell I prefer the hidden door handle look