My detailed answer: You can get close with a stylized outline, but the exact outline is going to get someone sued. We exist to tell clients when they’re wrong, and what can be done about it. You won’t do the client any favors if you just execute what they say, even if it’s going to bite them hard later. In the end, you get more respect that way too.
Companies trademark various aspects of their designs – usually those things which make it extremely distinctive – consider the Aston Martin grille shape for example.
So they do have legal recourse.
Is your client a business which offers mechanical etc works on that particular brand of car?
If so, manufacturers can be aggressive in defending their intellectual property as they don’t want competitors (to the dealership) gaining any commercial advantage.
That being said, whether a legal challenge is likely or not is largely beside the point.
The fact it could cause issues means it’s worth avoiding now rather than having to deal with the inconvenience / hassle once it becomes an established brand logo associated with your client’s business. In which your client would need to start from scratch again with hos branding.