So the D1 needs 5V DC. It can't take 12/24V aircraft power directly. So first, that means that you can't just cut off the male end of the cigarette lighter adapter and wire it directly to aircraft power, as that will then put 12V into the D1. Doing this WILL damage it (and there are warnings all over the manual about only using Dynon power adapters with the D1.
What you can do, though, is get something like , which you then connect to your unaltered D1 cigarette lighter adapter. You then connect its bare wire ends to your aircraft power. Voiila!