You should ask beforehand before doing these...all you do is copy that number plate to existing skins other people did, in my cars case those two TTM and Brownninja have made, same with the eboo's Kadett.
Since these skins are by default with cars, I think that most users are not stupid and will saw that skins are from the original car because they must download it, moreover the Alzen skin is a full redone, you can compare them if you want, I wasn't happy with the skin and I remade one using my own AO, I just used your skin to create a mask for colors in PS.