Well you aren't referring to a truck or even a vehicle. However I agree that your example product is intimately related to the trademarked item just as it is in this case. That's exactly why I'm wondering about precedent. It seems overly broad to me, a layman, but could well be the established status quo.
I would naively expect it to depend on whether the mark could reasonably be confused by a customer with the name in question. To that end fordboard and gitclassic seem problematic since they read like two separate words, one of which is the protected mark. In contrast, something like gitea seems like it ought to be in the clear - no one is ever going to think "git [space] ea huh wonder what ea by git is". (Ford should totally release a vehicle under the name Board that would be hilarious.)
> it is better when there is an overlap in the distinctive sound of the two words.
From the article you linked - this matches my intuition and is largely why I feel like gitea ought to be in the clear. Unfortunately it seems to be about trademarking portmanteaus as opposed to the creation of portmanteaus using one or more trademarks. (More is better - my next terrible idea is gitzurite.)