I've been using a mixture given to me by a professional detailing guy years ago with good success.  Clean the interior first with Windex or something mild.....take 1 oz. of lanolin & 3 oz. of clear virgin olive oil..........warm the solution up so it mixes together.   Heat up  the interior of the car (run it with the heater on high for awhile) and rub it/work it into the leather with a soft sponge.  Use the solution sparingly since it is quite a gooey mess.  I leave it on for a couple of hours so it sinks into the leather.  Wiping it off is a bit of a chore so keep  the car warm while your doing it.  Let it sit for a day and wipe it down again since it has a tendency to sweat a little.  It will leave a nice satin shine and has  kept the leather in all my cars soft and pliable for years as well as preventing stains from sinking into the leather.  I've never found  pure lanolin sold in stores but you can "Google" it on the internet and get it at a reasonable price.

 

Denny