I have changed 2 ignition coil in less than a week. Car still rides rough. on 2008 Hyundai Elantra

What causes the ignition coil to go bad. Is there another problem other than changing the coils?

Asked by for the 2008 Hyundai Elantra
I was told that the engine gets really hot on the side of the coil pack. It is recommended that you cake the engine side of coil pack with electricall gel. Three years now without a problem. Also they are usually about 25 bucks from auto salvage yard....alot of parts are new and taken off totalled cars...they save me a fortune in parts and most times if you find a good yard they will take it off for you and have it waiting for you if they remember you. So chew the fat with these people. When your one of us we tend to go out of our way to do good for a brother or sister wrench slinger.....Marvelous.