I recently purchased a 2015 Honda Civic EX-L. Of course I test drove the vehicle in the daylight hours and didn't realize until that night that the headlights were flickering badly when the engine was running. I immediately thought alternator or battery. I went to Advance Auto and the checked it, but both tested just fine. I took it back to the dealership where I bought the car. In the daylight, they could not get the headlights to flicker. Every once in a while you could see the side markers flicker...but that was it. I'm going to take it back out to the dealer this week for them to look at again.

Any ideas what could be causing this?