Hey Mark...
I'm checking my big tether book here...There's kind of hard-to-decipher stuff here, because there are so many varieties of Ford F-series trucks... However, there is a bullet that says,
"For 1989 and later models, Ford will pay their dealers to install tether anchors (Program R7C). Tether anchor hardware can be obtained free of charge from any Ford or Lincoln/Mercury dealer"
So remind him politely of a policy he may not know, and you should get your tether anchors for free. Try calling 1-800-392-3673 (Ford Corporate) if you need to deal with people "higher up"
If you happen to be using a lap/shoulderbelt for seat installation, with a Britax with the shoulderbelt lockoff engaged, the crash tests are very good, almost as good as a seat being tethered...but still not *quite* as good as tethered (that crash test of the maxi cosi posted earlier, has those lockoffs too...).
Good luck!