I had just recently gotten some sad news from an MT pal , that you must have commercial insurance for your vehicle if you apply vinyl lettering, etc to advertise your business.I called my own ins carrier (USAA) & they interviewed me briefly & sent my request to their underwriters. I just got a call back this afternoon, okaying my window decal with no change at all or cost adjustment to my auto insurance policy.It pays to do your homework. I did ask what the consequences would be if the underwriters had decided that it was not okay. Worst case (since I did offer the info to them) would have been for them to connect me with a commercial auto ins carrier in their networking circle. (USAA doesn't do those policies) I also asked if they thought everyone should ask, or would this be a standard underwriting decision. They said it would be best to check it out with each of your own policy carriers as each weighs the risks & costs according to their own rules.Anyway, just sharing.Jill/Sagetherapist