I can't comment on the Ford world, but with other OEMs, contractors are also raked under the coals on price. The OEM may pay big bucks, but you aren't going to see it. They keep that added cushion as profit in the event you ask.
As a multi decade contract employee, I learned a few things in my time...
First, no one is there for your financial interest other than you, so still do great work, but stop being so nice. Second, do a better job than those around you always, for reasons I'll explain later. Third, every year or two, I made a point to document your successes, growths and wins, as reasons why you deserve a raise, and be assertive in delivery and follow through with the Rep. Doing so I've received five 25%+ raises each inquiry, well the last one was less as I reached cushion cap in which they couldn't do much more. If you don't ask and nicely push/assertively, they'll never offer. You almost need to not care in a way.
Lastly, going back to what I said about trying to be better than everyone else, or at least to be a grade A candidate. Always deliver on quality. Be nice, be respectable, be professional, and be a team player. Our OEM had a policy that NO salary could endorse or recommend a candidate. I walked out of that company with 2-3 dozen letters of recommendations and endorsements from direct hires. They didn't care about policy, or whether it violated policy. Some even said you write the letter and I'll sign it (I didn't but that says something). Good people WILL absolutely stand behind good people, and do the right thing.
When I dropped these references/endorsements off to my future hiring manager, the looks on their faces are priceless. Needless to say, I had multiple offers for my future job, all in the same week. And, that is the absolute truth.
Beat them at their own game.