Also, in terms of the size of the civic (which i'm still sure just looks larger than it is in these images) Other spy shots that had people in them standing next to the car for comparison shows that the civic really hasn't grown that much. I'm pretty sure it's the body style giving the illusion of size and length when i believe most of the growth has been in the width of the car.
BUT. Just for fun, i was wondering what the specifications were for a car to qualify as a "compact" in the US and not as a "midsize". Turns out, and i think i already knew this, its determined by interior volume of the car. Which means in theory... the car can be as large on the outside as the automaker wants... as long as the interior doesn't go over the max cubic feet of space of a compact, it's still considered a compact car, which is weird, i feel like there should be weight and length/width restrictions applied too. But i want to say the Elantra is actually classed as a midsize because of it's interior volume despite its compact car exterior size.
From what we've seen of the interior so far it doesn't look like the cabin has grown that much. Probably alot more shoulder room due to increased width and more rear leg room thanks to the increase in wheel base. But i'd say the interior still falls under the compact size restrictions.
Again, i'm pretty sure it's just the angles and photos that are making it look so long. Pictures with people in them don't seem to have the same lengthening effect and assuming the concept car has similar proportions to what the production coupe will have, it hasn't grown all that much at all based solely on comparisons of people standing near the car assuming a height between 5-6 foot tall.