Yamaha has done a lot of engine development for cars over the years. As mentioned above, they did a couple engines for Ford including the SHO V6. The 1 and 2ZZ - series 1.8 inline four has been used in a ton of Toyota and several GM cars as well as the Lotus Elise destined for North America. In fact, you can find a lot of Yamaha logos on various engines throughout the years. I had a first gen MR2 that had a Yamaha design top end. A Yamaha designed V8 is used in the Volvo XC90 and has been adorned with two turbos and put in Noble super cars. They also did the V10 masterpiece used in the Lexus LFA
It's very interesting all the technology sharing that goes on between competition.