BUFFALO, N.Y. (WIVB) – They might be cheap and innocent looking but those car air fresheners that hang on your rear view mirror could do serious damage to the inside of your interior if you don’t follow the instructions to the letter.

Just ask Jim Diavastes. When the air freshener in his minivan was hanging from the rear view mirror it was a distraction, so he dropped it down to an air vent tab, where it rested against a control knob on his dashboard.

One morning, Jim saw the freshener was sticking to the knob, so he tried to get it off, “and as I pulled it, plastic stretched off with it. So I yanked it off all the way and I noticed it looked like there was some goo on the knob.”

The air freshener had actually caused the knob to melt, and Diavastes surmised, “some chemical inside this air freshener doesn’t like plastic.”

Jim isn’t alone: A web search shows many of these hanging car fresheners have also melted plastic or damaged car upholstery, but the package for Diavastes’ air freshener includes cautionary instructions, as do many other car air freshener packages.

“Air freshener should hang freely to avoid staining of any surrounding area. Do not allow contact with upholstery, plastic, painted or varnished surfaces.”

But Diavastes points out, it doesn’t warn you of the other consequences, “I found a number of listings across the country from people with various makes and models of cars that say, don’t buy this brand of air freshener because it will melt the dashboard.”

There have been reports of the car air fresheners causing hundreds of dollars worth of damage to auto interiors. Fortunately for Jim, his damage is minimal.

“It destroyed the rear vent knob, and it melted what seems to be the top layer of vinyl on the dashboard. I am scared to touch it because I don’t want to leave a fingerprint or make it worse than it is.”

We reached out to one of the better-known air freshener manufacturers, but a spokesperson told us they have a company policy of not commenting on industry news. One knowledgeable source indicated many of the fragrance oils have a petroleum base that can stain and get overheated.WHAT OTHERS ARE CLICKING ON RIGHT NOW: