In my experience Mazda avoid using the number 4 for any of their models.
i.e Mazda 121, 323, 626, 929, 2, 3, 5, 6, MX-3 MX-5 Rx-3 Rx-7 Rx-8 CX-3 CX-5 CX-7 CX-9 and so on
There are several unlucky numbers in Japanese. Traditionally, 4 is unlucky because it is sometimes pronounced shi, which is the word for death. Sometimes levels or rooms with 4 don't exist in hospitals or hotels. Particularly in the maternity section of a hospital, the room number 43 is avoided because it can literally mean "still birth". When giving gifts such as plates, they are normally in sets of three or five, never four. (source Wikipedia)
So I'll go for something like an updated CX-3 or CX-5.
