[Fnoord]

Great question as the animal is already dead.

Depends on how strict the vegan is to the letter (you can almost compare it to a religious -ism). A vegan doesn't eat any product containing ingredients from a dead or alive animal. For some, it goes as far as "using" instead of "eating" (IMO that gets ridiculous cause would you accept money from a meat eater?). As you can see, there is not one agreed upon definition.

As for the specific subject you brought up see roadkill cuisine [1]. Fur is made from roadkill as well. I'd expect that is more common than eating roadkill, but I am unsure.

There's a vocal part of the vegan community ("vocal vegans") who dislikes all of the above. Its like the mob. How big the group exactly is, I don't know, and they give vegans at a whole a bad name. Make no mistake though: they do not represent the vegan community at a whole.

[1] https://en.wikipedia.org/wiki/Roadkill_cuisine