I purchased illuminated sill for my 2004 eE500 from my mercedes.com. Originally, I was going to have the illuminated sills mount on top of the existing sills, but that would make the sill too thick, causing it to rub against thte bottom of the door. The tape that was attached to the sills are so thin that it was recessed inside the illuminated strips, therefore, they would not stick to the door sill. However, by adding additional tape to the attached tape made it thicker, therefore easy to stick to the door sill. The wire of each illuminated sill is attached to each door switch, therfore each sill will illuminate independently only when that door is opened. If any sill won't lit up, I will know which door switch or wiring is causing the problem. I did not install the sills personally, but I watched as the installer install each sill.