Thanks tomherb! I tried the softer stuffs first as I did not want to make the plastic brittle, I heard some stuff could slightly damage the plastic. I was lucky it worked the first time!
I did some other tests, this time with cardboard hahahah I placed 2 L shaped pieces, on on each side of the bottom of the chassis. Then I tried to find a way to brace the part that will hold the strut,when you think aboutitthis is where all the weight of the car will be.
and also thought of stiffening with rods and balljoints, but I figured I would be better with aluminium plates bolted as those would have resistance in more than 1 way (a rod with balljoints is strong only on pull and push, not sideways)
On the other side, I tried to find a way to hold with what woud be 3/16 inch aluminium pieces, with some folds to attach with the L pieces:
Some pics of the parts I have. After I bought the lathe, I tried to do an universal joint out of aluminium. It worked out good but I thing it would not hold very long as aluminium is pretty soft.
I have 2 types of balljoints. The big ones will mostly be on the front, and the other ones on the rear.
Here is what I did to the pulley. Will do the same to the other one.
Frederik