Collision-Mesh issue (car sticks to mesh)

Hi guys,

i am getting crazy with creating a working collision-mesh. There are "good" sides of the mesh and some sticky sides with super glue.


Like the screenshot shows, all convex sides acts like expected. Could it be, that a collision mesh have to be convex as a whole??



EDIT

I tested it with a convex mesh and it works like expected, so am i right?



I used SketchUp for the model and set visible mesh as collision type option

 

What do you mean by sticky? Like when you hit the wall the cars bumper gets slightly lodged into the wall?

 

yes ... i checked the normals too. They all point to the outside ...