If you have hard stiff dry leather and are not needing your car for a weekend, try this:

Use Coconut Oil, commonly found as a hair conditioner.

Apply liberally to the effected areas, let it sit for an entire weekend, and before use, wipe off exxcess.

If you shut the wondows during this process, the leather and coconut smell is pretty nice.

MAKE SURE TO BUY THE PASTE TYPE COCONUT OIL.