http://jalopnik.com/cars/jalopnik-fanta ... 327268.php
Murray shopped around for an engine, initially trying with Honda and then Isuzu. Honda was a real possibility, as their engines had been powering McLaren's Formula 1 cars for some time. Honda eventually backed away and McLaren decided that as nifty as Isuzu's 3.5-liter V12 would be, they needed to go with a manufacturer that had racing cred.
When Honda refused, Isuzu, then planning an entry into Formula 1, had a 3.5 V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the F1. However, the designers wanted an engine with a proven design and a racing pedigree.
Description in English paraphrases the above two statements, language is Japanese, may or may not state the same.
The engine was used in the Lotus open wheel race car, considered by McLaren, and eventually found its way, or was intended for use in the Como concept car.
The Como was a mid engine sister car to the Buick Wildcat concept car. The Buick had a GM V8, and the running version of the Como may also have had a Chevy V8. The Como appeared at the 29th Tokyo Auto Show.
The Isuzu V12 specs are 3.5 liter displacement and 740ps/13500rpm, 42kgm/11000rpm.
The engine is currently believed to be in the "basement" of one of the Japanese car club presidents. One problem with this theory is that Japanese homes do bot have basements. But the suspected owner has more than a few other goodies that indicate that if he does not have the engine, he probably knows where it is.