Folks, a bunch of you are missing the point.
Ford (or any other trademark owner) does *NOT* have the ability or obligation to decide whether or not to pursue a use of their trademark, period. If the trademark owner does not actively take measures to protect it, they will *LOSE* their trademark. The courts in this country have said for years that it's a court decision on infringement, and a court's alone. There's a monetary value attached to each and every trademark and servicemark Ford owns, and they can't afford to let anybody use it without restriction.
I don't know what the status is on Ford's use of the name Ranger. If Ford no longer maintains the trademark, it's fair game. But if Ford does own the term, anybody who uses the term, and exchanges money as a result (say, a paid membership to TRS?) Ford has a responsibility to their shareholders to go after the infringement.
Enthusiasts or not, you absolutely, positively may not use somebody else's trademark. You can reference it (comparative advertising,) but you can't use it in your own line of work.
The problem isn't Ford. They're between a rock and a hard place. If you think for a second that they don't get the value of the enthusiast market, I have some ocean front property in Idaho for sale. If they don't go after infringements, their balance sheets will go down in value, and the shareholders will vote in changes.