Opposing 2 bangers can be smooth but they need to both fire at the same time. A little rock and roll never hurt anyone anyway.
I would love an underpowered car if the darn thing would net VERY high FE. To me a single or 2 person vehicle should never weigh more than 1000lbs, thats where the magic starts.
"Since Fiat bought Chrysler we may see this engine in a few small cars. Like maybe offer the 2 cylinder in a Dodge Viper?" Might as well put it in the Dodge Ram 1500 crewcab while you are at it.