Rubbing Alcohol.

If you service your car at a particular dealers site, you could try there. The service folks have the proper cleaning materials for leather. I personally would not use Windex.

Our boat canvas/leather place told us to use shave cream.

Thanks for all the helpful suggestions. I knew I could count on this group! After some thought I've decided that probably the suggestions to let the pros do it, or at least get their advice is probably the one I'll go with. At least it gets me off the hook, and I'm extremely leery of making the situation worse. At my age, perhaps the message is I shouldn't be wearing jeans out in public anyway. Sigh.

Maybe all need to make beautiful quilted slip covers for our cars.

oh! I like the idea of quilt seat covers!

I'd avoid Mr. Clean erasure because it removed the color from my car seat. Cost to replace leather $200.

I had the same thing happen to me--beige leather seats and the dye from blue jeans was rubbing off on them. I just used a leather cleaner on the seats and had no problem getting the blue off.

The leather cleaner sample that came with my car worked on getting the blue from jeans off of the seat. I told my son when he takes it in for the 1st oil change to purchase me a bottle from the dealer.

Wow, how strange! My car has 2-tone leather seats (dark & light grey) and I wear jeans all the time - never had a problem. My car is about 1-1/2 years old now. I tend to wear lighter colored jeans though, not the really dark indigo. Interesting!!

You're never too old to wear jeans in public, though, is my opinion! Of course, I'm 40 and dye my hair black and bright purple and wear Chuck Taylor sneakers, so maybe I shouldn't be listened to for fashion advice. ;-)

recently had an ink pen break in my car, before I knew it I had ink EVERYWHERE, door panels, seats, hands, clothes, every where I looked I had ink. Alcohol wouldn't touch it neither would vodka. lol I was miles from home. I went to NAPA, an auto parts store, and they sold me a bottle of cleaner that works on leather and fabric items. Can't remember the name but it worked like magic, cleaned the car, me, my clothes, leather coat and everything it touched. Had a slight lemony odor for a while but it worked. Try an auto parts store, they can help.