On my rs6, my hid lights have a hard time igniting when it gets cold outside. I have replaced both ballasts with Oem ones and I run true Phillips 6000k bulbs. I have to turn the light switch a couple times to get one sometimes both to come on in cold weather. Do the c5 model audis have any issue with poor headlight wiring that could cause issues in cold weather. In warm weather, no issues. Thoughts by anyone?