I have order a new cheap universal licensplate holder to try another way. Waiting to it drop in my mail box. I'm not going with a side mount, than it rather be the stock way.
I've already change for Customled integrate brake/turn signal, that gives me a empty socket for the rear light I can use for the licensplate light if I ending up with another solution than stock. What other people did, I don't know. Thruly reroute the wiring...