Collision models are messed up

Hi,

Recently I've been making some custom models in Sketchup and importing them to BeamNG. Sometimes it works great and sometimes it does not. Here is an example.

(imported from here)

Every time I touch the model it sucks me into it and glitches out. Seeing as Sketchup doesn't export with any collision mesh I change it to collide on visible mesh.
I know most of you will probably tell me to not use Sketchup, but I'm certain it will work somehow. I'm not really keen on changing software because I have been using Sketchup for years.

The loop you see in the background was made in Sketchup and is set to collide on visible mesh. It works flawlessly so I know I can get it to work every time somehow

It would be a life saver if anyone could help me

 

If the collision works that way at some but not all models, i would guess the reason some models are eating vehicles are unaligned normals on the mesh.
I never really used sketchup myself, so i can't advise anything special but to have all normals aligned to face the same direction...outside i think.^^

 

I would like to see a wireframe of this sketchup mesh. From what I've seen, sketchup produces really crappy poly layouts.