There are many grades of vinyls used for making decals and stickers. These vinyls are manufactured in many countries around the world. However we have found that many of the cheaper grades of vinyls, made not only in Asia but many other countries seem a bargain but the adhesive on them is very aggressive and when removed will often leave a lot of the adhesive on the surface where the decals or stickers were previously adhered.
If not fully removed, this left on goo will attract dust and dirt just like bees around a honey pot and soon the old vinyl graphic will reappear as a dirty shadow .
This generally occurs on motor vehicles that have been sold and the original owners graphics have been removed but the surface has not been cleaned correctly. Apart from detracting from the appearance of the vehicle it isn’t helping the new owner.
Many folk try gas, paraffin, mineral turpentine, alcohol and other kinds of chemicals they think will remove the goo but these are not the best method and are generally flammable and that is dangerous.
A simple cheap method of removing this offensive and ugly grey or black shadow is cleaning it down with Citrus cleaner or eucalyptus oil. Spray this on and then rub with a rag or soft brush, you may have to let it soak in for 15 to 30 minutes or so and then wash off with water and using the same soft brush or a rag.(Eucalyptus oil is also a fabulous way of removing chewing and bubble gum from surfaces where it has been trodden in, especially carpet).