I'm really surprised to hear anything positive about the DDM kits. I just got them and the instructions tell me to insert bare terminals into the old light sockets? WTF?? No way would I do that, it wouldn't stay in place and it's not sealed at all. No idea why they would send them this way instead of just putting on a receptacle for the bulb socket.
I got the H11 kit, and the bulb size was not to spec, it wouldn't go in. I forced it just a tiny bit and the cheap plastic edges on the bulb snapped right off.
And the strain relief going into the box clearly wasn't doing anything. You could move the cable in/out a few mm easily. This could lead to failure over time. Mine came direct from a factory in China, and I have enough experience with manufacturing in China to recognize when something is made as cheaply as possible with little to no quality control. I just hope I can get my money back.