Actualy Yamaha has ben building motors for cars for a while the 3.0 in Ford Taurus SHO from 89-95 is all Yamaha motor!

http://www.superhighoutput.com/about.php

 

yeah i know. my bro had the 3.4L v8 sho. that thing would haul! it was listed as a ford/yamaha engine, but FORD opted to glue the camshafts together in this engine so that has been a known weakness in them. the v6 was the better engine though.
yamaha has also helped GM, vovlo (4.4lv8), and just about everyone else with engines. oems you would not even think that needed help have contracted yamaha to help them design/build engines for them- even the great wonderful cant do wrong, Toyota.

 

Toyota has a 5% share in Yamaha and Yamaha owns 500,000 shares in Toyata. If ever notice a Toyota or a Yamaha add and if there is a vehicle and a sport machine of some sort it will be of one of there own!

http://en.wikipedia.org/wiki/Yamaha_Motor_Corporation