The air freshener looks nice and makes the car smell really good (but you have to get the right scent, some of them are kinda yucky). I don't like steering wheel covers on some cars, just ones that have a not-so-nice steering wheel. My Dodge has a leather-wrapped steering wheel, which makes a cover not really necessary. But some cars have really nasty plastic steering wheels and covers are nice to have. Floor mats are extremely helpful from keeping dirt and water off the carpet in the winter and springtime. So no, they are not "useless" they all serve a very important purpose.