 Never. I did not drive behind them. I watched them from the window sill, rest assured. No. You knew where I was going with that. For those of you who may not know this, in parts of the country, in the South being one of them, especially 50, 60 years ago when it was probably unknown with some of the dangers, they would use diesel fuel as a dispersant material and malathion because it would stick to the diesel fuel so that it would be deposited over everything.