OK, Counselors.  I ask this question merely as a thought exercise, so forget
about any tacit contract thing (i.e., $$$) because it ain't happening here.

Recently, there has been some talk regarding original equipment (OE) parts
sold by the manufacturer of a vehicle through their dealership network as
opposed to original equipment manufacturer (OEM) parts which are made by the
same vendor who supplies the vehicle manufacturer, but which are sold to the
end user via the aftermarket parts distribution network.  The OE parts are
branded with the car company's trademark, while the OEM parts are identified
with the OEM's trademark.

Now, for the hypothetical: Would a prudent and conservatively dressed
attorney, retained by a car company, advise his client to include in his
contract with any OEM a prohibition forbidding the manufacture of parts by
the OEM to the same specification which the car company had formulated and
for distribution by anyone other than the car company?

I know if I were as bright as Soichiro Honda or Dr. Porsche, I certainly
would want such intellectual property, which came from hours of expensive
research, testing and technical writing, to be protected.

Rich