I just got a 1990 300zx with black leather seats and it appears that the previous owner didn't do much to keep the seats in good shape. Now they feel kinda dried out and stiff, I have the lexol cleaner and conditioner and i'm wondering if using the conditioner frequently will restore the seats any? i've applied it about three times over the last two weeks and havn't noticed considerable difference. Might i need another type of product(s)? anyone with ideas?