insurance = the same
running costs = very close to each
tax = the same
if you're not too fussy option wise you can get either for a very identical price
But apples for apples, the Megane is the more expensive car. It stands to resason that some buyers look at the Clio, at least thinking that the Megane is out of their budget. It's no bad refelection on either car, but IMO it's basic common sense to accept there is likely to be some truth in it - hardly worthy of mention though really