Made for skin, not your leather
Sunscreen is obviously developed to go on your skin, with all sorts of interesting additives to help protect you from the powerful UV rays. These ingredients are not real car friendly though, which is annoying when you find them on all parts of the car after a day on the water or at the beach (especially if you have kids!). With most sunscreens being water resistant, many traditional interior car care products will not remove them, and if they are left on for a long time (like many months), it can become seemingly impossible to do it safely.
The reason for this is two of the main ingredients used in the formulas; namely polyethylene glycol and titanium dioxide. These work a treat at reflecting light and protecting us from UV, but when put on leather, it will leave that white residue and embed into the top coat of clear polyurethane and the longer it's left, the harder it'll be to remove.
The biggest tip we can give you is to clean any sunscreen off quick. Living on the Sunshine Coast in Qld, Australia, we deal with sunscreen a lot! From this experience, here are our three best methods to safely clean these annoying white marks from your cars leather.