Here are a couple pictures of my running lights in the same dark garage. Again, there is no external light getting in. The doors are closed so the dome light is off. The only lights are the running lights.

In these two photos, the driver's side brake and turn signal are on, so the driver's side lamps may look a bit brighter than the passenger. I was trying to show the difference but it all kind of washes out in the picture.

Again the camera does a good job of exposing the scene, but honestly, in real life, these things are bright. When that brake light comes on and if I look at directly, it literally gives me a headache. It will make red spots in your eyes it is that bright. Unless the guy behind me is in a coma, he's going to know I hit the brakes.