You can keep it really clean with just a few simple things. I use about 4-5 products all together for my interior. Start with warm water in a 5 gallon bucket, you only need about 2 gallons at most. Get another bucket as a rinse bucket. Mix it with Meguiar's APC interior (green) ranging from 4:1 to 10:1 depending on how dirty to clean it is, respectively. Soak a microfiber and ring it out back over the bucket. Firmly wipe over the interior, including leather seats. I would check first if you get a different APC because Meg's APC Green has leather softeners and at a mild dilution is fine for leather. Once this is done, treat the interior trim with Vinylex. Spray generously on a microfiber and then spread across the trim as to not create overspray spots. Next, move onto the leather seats. Use Lexol Leather Cleaner for a deeper clean if your seats are really dirty, and then move on to Lexol Leather Conditioner. If your seats are really dry, let the conditioner sit on top for a while and soak in. You even might want to turn the heat on in the car to open the pores of the leather up or use a hair dryer. You can buff any of the products to a matte finish if you like after they dry. Obviously vacuum and clean the class afterwards. When cleaning the glass, make sure you go over it again and rebuff the glass with a microfiber or you'll find streaking. I find this prevalent with all of the glass products I've tried, such as Stoner's Invisible Glass.
I thought I was clean until I did that session the other day. The rinse bucket water was filthy. I promptly dumped it out and looked around to see if anyone saw me do it. I was embarrassed.