Http Status Code For Validation Failure Related To An Item Which Doesn't Exist

Question

If I have a method to create a "car" entity, and as part of that it requires a "manufacturerID" but the manufacturer doesn't exist, what status code should I return?

400 to indicate that the request was invalid

or 404 to indicate that something related to the request doesn't exist?

I'm hesitating against 404 because it may imply that the endpoint doesn't exist, which isn't true, it's one of the parameters that doesn't exist.

Would 404 with an explanation of what doesn't exist be most appropriate? Or the more vague 400?

Answer 1

400 because the request is malformed if it contains a none existent manufacture.