Regular vacuuming and dusting of your car's interior is the best way to keep it looking good. However, surface cleaning alone is not enough. Two to three times a year you will need to detail the upholstery to keep it looking its best. Personally, I like products that leave a nice matte finish or low sheen, but that is personal preference. My favourite detailer is 1z einszett cockpit premium, but I also like the protection in ultima interior guard plus.