Some women will adopt the niche interests of men they like. Sometimes it's a favorite sports team of a father or boyfriend. Sometimes it's video games a father or boyfriend introduced them to. Sometimes it's cars.
The important thing is not actually rooting for her team or playing her favorite game or driving her favorite kind of car. Rather, it is establishing attitude similarity with her on the subject. She's just looking for clues you are similar to the sort of men she likes, and the sort of men like that [team/game/sport]. There are also many, many men who like that [team/game/sport] whom she does not like.
Don't get too distracted by superficial things. People can say they love a car or a type of animal or a politician, but just because you have that car or that type of pet or root for that politician doesn't mean you get an easy 'in' with that person.
You still must go the standard route: improve your fundamentals and deploy some game.