> There is also the argument that absent confusion, the third party is essentially looking to free-ride on the goodwill of the brand owner.

But can one consider that infringement? I would assume something like that to fall under a fair use doctrine in most jurisdictions.

Let’s say I invent a set of amazing tires for Audi cars (they only fit on an Audi car), and I sell them for half the price of a set of official Audi tires. I brand these tires as “AmazingTires for Audi”, with a disclaimer that I am not Audi, but a third party.

In this scenario, you’re riding on the goodwill of the brand, and the brand owner might oppose. However logically I would assume something like this not to constitute infringement, as you are not actually damaging the brand (if the product is good) and there is no other way to describe your product without using the Audi brand name.