Clean the Leather
This may sound extreme, but if you've got leather upholstery, buy a leather-cleaning kit and keep it in the vehicle (one brand is Leather Master Leather Care Kit with Ink Lifter). Because, if you clean the oops right away, you really increase your chances of a complete cleanup. If you wait, lipstick, ink and dye transfers from clothing (and plastic shopping bags) can set permanently in as little as 24 hours. Pretreat the leather with a conditioner before you start the stain removal process. Wipe the ink lifter directly on the pretreated leather and rub it in. Let it sit for 30 seconds, and wipe it with a clean cloth. Then apply leather cleaner and the leather protection cream.