On the Regal..I found that the bulbs are special for the center directionals. I'd do fine for a bit then have issues, kinda similar. Now the Regal is diffierent enough..but check the kind of bulb it is. Not just a 3157 but there's a letter code that goes with it that describes the type of electrical system. I think it's an SR bulb vs a regular. Not sure if that's the issue. Might be.