The default model is 2mm thick and arround 40cm. 

It was abviously to large for my ender3 or A1 mini so i split it in the middle.

They are the two midle part in the files. You can fix them together with glue.

You can scale the parts as you want but don't scale all the axis the same otherwise the tickness will change too. 

You can fix it on a wall with small nails or double-faced tape.

https://www.printables.com/model/697218-porsche-911-992-gt3rs-silhouette-wall-decoration