-Could you tell us about the design techniques, the know-how you have called upon to design the exterior?

Sawai : That's top secret (laugh).

-Within the limits of what you can reveal.

Sawai : Maybe we could talk about the work done by Mr. Toriyama on what makes a 5-door design look like a 3-door one.

-If you please.

Toriyama : The previous model's 5-door design has been praised for its sporty look. One reason is that despite being a 5-door design, it actually looks like a 3-door. But ,hiding the rear door handle out of view alone could not explain everything, so I started looking at what made it look like a 3-door.

Nishimoto : During our study of the market, we received many complaints on rearward visibility. The thickness of the rear pillar and the rear door handle located in the lower back of the rear window trim make for poor three-quarter rearward visibility. This makes changing lanes difficult. Although word quickly spread around, customers have kept buying the car for its looks. But, this was clearly one of the first things we had to improve in the New Civic.

Toriyama : We wanted to find out how much we could improve rearward visibility without losing the 3-door look. So I embarked on a research titled "Research on what makes a design look sporty," comparing 3-door and 5-door designs within Europe's C-segment.

Sawai : You looked at quite a number of vehicles didn't you?

Toriyama : Yes, indeed. Two points attracted my attention. The first point is the ratio of the side glass area to the entire side surface. The second point is the ratios of the front and rear window glasses within the overall side glass area.

-Surface ratios then.

Toriyama : Yes. If we look at the ratio of the side glass area to the entire side surface, my research reveals that 3-door designs have a smaller side glass ratio than 5-door designs. This explains why 3-door designs have a smaller-looking cabin which in turn serves to create a more personal, sporty feel.
Next, if we look at the ratios of front and rear window glasses, we realize this is actually the defining element in whether the car has a 3-door look or not. 3-door designs tend to have smaller rear windows.

-Yes, that would be the general assumption.

Toriyama : Maybe, but now it can be quantified. 5-door designs have front and rear window surfaces averaging out at 50%/50%, whereas 3-door designs have a front window representing 67% of the total side window surface compared to 33% for the rear window. The difference is quite significant.
I then checked the ratios of the front and rear window glasses in the previous 5-door Civic and found out that it is even smaller than the 3-door average within the C-segment.

Sawai : It actually has a more 3-door-like front to rear window glass ratio than the 3-door average within the category. Interesting isn't it?

Toriyama : So now we knew we could increase the surface of the rear window glass, and by how much, without losing the sporty exterior look.

Nishimoto : This is how we were able to lengthen the rear window glass area backward quite significantly for much improved rearward visibility.

Sawai : All without sacrificing the 3-door-like look.

Toriyama : Looking "sporty" or "emotional" is a question of feeling, of perception. But rather than intuitively reducing the rear window surface ratio, we wanted to address the issue logically and quantitatively—the Honda way.

Sawai : A logical, quantitiative approach is important. But whether this is the definitive answer is another issue. This research has led to the discovery of one lead, to the drawing of one line, but whether the numbers that have been found are definitive numbers or not, we cannot say for sure. Should the objective change, we will need to look at the problem in some other way. However, one thing is for sure. It takes much more than just drawing fancy-looking sketches to design a car. It is also about painstaking research like the one just described.

Toriyama : Painstaking it was (laugh)!