That idea has been tossed around on the EV list a time or two and it's a decent one IMO. The electric motor would best be utilized for accelerating from low speeds, and to simplify it greatly, regeneration could be omitted in favor of just plugging the thing in when parked. 300 lbs of lead-acid batteries would provide all the oomph the average person would need around town for getting up to speed with the ICE off. A setup like that could easily beat highway EPA estimates with city driving (just like current hybrids handily do).
I like that idea, I wonder how viable it would be. I have the May 1985 issue of Car and Driver with the twin engine CRX article: "synchronicity". It still got 29 mpg with only the front engine on lugging the extra weight of the second.
Ha ha. I remember reading a sport-compact-car article in the early hybrid days with a "Hybrid CRX". I thought, "Wow", a super fuel efficient CRX! I can't believe it's in this magazine! I gotta see this! ... It was a double engine CRX, just like your article.