Sorry, I disagree about leather. There are special cleaners and conditioners for leather car seats. I periodically clean my car's seats with the cleaner then apply the conditioner.

I've had my car for more than 3 years now and the seats are fine. However, if you have a woman with you in the car it's a different story. Their clothes often have sequins and other additions that do tend to scratch the leather but not too bad, though. Besides, a lady in the car is always a welcome companion.