Have been working on with the front now, the overall profile of the second plate and arranged holes for the fan. Had to cheat a little by inserting a thin plywood plate behind the hole. It was difficult to spit out the profile of the car, then took to sawing out the hole with a jigsaw first, and then made round edges with a cutter.
End chat, here are some pictures:)
The first thing that was done was to cut out the hole with a jigsaw:
In the back I attached a plywood plate, so that not only is a hole there, but the mounting of the fan:
Drill holes for the fans:
Used the cutter to make round edges, just like on the second disc:
Here I have constructed both records:
And here I tried with only one disc in fornt:
Here is the result:
Thanks to the sponsors!