Remember: if within a CASE statement the WHEN clause is TRUE, the following WHEN statements and the ELSE statement is not executed anymore.

So if some data in your example contains the value "fictive Buick Chevron" it will return "Chev" and not "Buick". Only when the data doesn't contain either "Ford" nor "Chev" nor "Buick" it will return the "All Cars" value.