Sorry to burst a few bubbles, but this sterotypical image of the Japenese car industry isn't the case.
Japanese bike manufacturesr have played with things in engines only now being tried in cars. Honda had a ceramic engine they raced nearly 20 years ago !
Power/weight ratios the Japanese engines are hard to match even now.
Yamaha played with things in the F1 engine that are STILL kept confidential !
Yep, they copied - it's no secret that Maxda bought lots of Lotus Elans before the designed the MX-5. But, be honest every designer does that. It's just that the end product is often better from Japan that makes it so obvious.
What is often misunderstood is the way Japanese companies co-operate. Yamaha are beleived to have passed on all the F1 results to Toyota.
There is a level of co-operation and sharing which is natural for their industry and UNnatural for capitalism as grown in the US of A.
At the end of the day I don't care if somethings is 'copied' to give us a better car or whether it's oriiginal. The best will win