What do you have to back that up?
Within the last couple of years books and articles have appeared making those claims. I haven't researched them. All I can tell you is that they were published by mainstream publishers and reviewed in the mainstream press. I take that to mean that they should be treated seriously. You might feel differently.
Here's a Google I just did in response to your question. I don't have enough interest to pursue it but you can if you wish. It's probably just as easy to do the same with Ford.