The deal is that many consumer leather care protectants have a nice "leather" smell to mask the smell of the oils/conditioners etc. Also some (many?) of them are based on silicone chemistries which are odorless to begin with.
The problem with automotive leather care is that most automotive leather is coated/infused with vinyl, so you really need to take care of it like a delicate vinyl surface. The only places where leather conditioners will really penetrate is the stitching or other areas with cracks.
Some leather is uncoated, and that kind needs to be treated more traditionally, e.g with a Lexol type product that has lots of oils in it, and so is ment to be good on uncoated leather surfaces as well.
The test is if you leave a drop of water on the leather. Does it bead up/float on the surface (vinyl coated) or does it soak in leaving a wet spot (uncoated)?
Lexol should be used lightly, on pre-cleaned leather, and then buffed off after 30 minutes or so. For really dry/hopeless leather, you can use neutral shoe cream with mink oil. But you need plenty of buffing to make sure it doesn't rub off.
Given that I like my leather to be shiny I've thought about getting some of that new Armor-all "ultrashine" protectant and using that as a final dressing for the seat leather.
