Actually-denatured alcohol followed by a few drops of dish detergent in a pail of warm water. Then dry with clean cloths and if any other stuff comes off on the cloth use a bit more of the alcohol followed by the detergent/water again.
To finish up use PLEDGE in the spray bottle and nothing else. Trust me and my upholstery specialist when you read this. The alternative for soft surface vinyl is LEXOL conditioner for the doors and seat trim.
One other thing-the vinyl may be so old that you will want to consider either replacing it or using a spray dye to recolor it.
Happy holidays