Can I apply for an appearance patent for my car sludge model?

No, you can't patent a car just because of its appearance. You must produce the whole vehicle and then sell it in the market. In this case, if a third party uses a car with the same appearance as yours for sale, it is an infringement.

But looking back at the automobile industry, people can escape the bottom line of legal infringement as long as they change. For example, QQ and SPARK are the most obvious examples.

If the landlord has a talent for design, he can submit a manuscript or go to the factory in person, which is highly probable.

May your dream come true.