I attended motorcycle mechanics intitute of orlando. I dont work in the industry anymore but during engine theory class, I learned a lot about how engines are designed and built. Inline threes have many merits. Theyre smooth, and more balanced than a four.
I think part of Subaru's charm is their unconventional designs. If they made a little four banger hatch it wouldn't be as "subaru" imo. I just think that bringing back a new Justy is a no-brainer. It would get better mpg's than Imprezas because its smaller, and the less conventional three gives it that Subaru authenticity. If they kept it under 15k it would be a great way of attracting more buyers to the brand and everyone who wanted a rugged, economical, long lasting econocar would be set!