I had Eibach on my 3rd gen for about a year or so and went through at last 2 leakers. Each time I had to call them to get a replacement. I got rid of them and went with Bilstein 6100 and 5160 and never looked back.
It looks like their design for the back door will allow for you to open the cap without opening the tailgate.
I know that has been an issue on other brands.