Hi Christa, What Dave said could help but just make sure that there's not to many Braso in the mix. I've been in the Valet buisiness for a couple of years and my dad used to walk around with bottle of braso, removing hard stains on the cars with it and I hated it, because i believe that it is harmfull to the clearcote on the paint. Now i'm in the chemical trade and supply mostly car wash and valet services. You must first determine what is on the van before applying annything on it, just to be carefull not to damage the paint surface. If you don't get any results, let me know and i will get in contact with you to help solve the problem.