My only option was leanding a rotary drill 18 millimeters. Now we just used that and drilled up to 17,6 millimeters. How ever the Aussies useless part said 18 millimeters. Drilling PU with 18 millimeters gives 17,6 millimeters. Excellent.
Here is the gap that is closeable without abusing the included metal part and bolts for fastening.
Here you can see that the included stabilazor rubbers are not up to the job. 10 thousand miles and totally shot.
The last bolt, six times placing the wrench tool per revolution. Also still room to stiffen it more.
The results, the yellow whiteline rubbers new installed where real crappy. The bar itself does not hold rust off very long but that is solvable. One should stop using that yellow stuff from whiteline, it is soft and it worn out oval. For driving, the car responds a lot better to road differences and it feels a lot mor solid at the back. Now my car is telling me what is wrong on the front (I have difference in settings there).
But Whiteline Flat out, indeed, their included PU did. Now I contact Whiteline aftersales and whine a bit, maybe they can tell me why I'm wrong with my assumptions that Whiteline has a nice stabilizer bar but you can forget the rest that they include with it. Newly installed! 10 thousand miles. After putting red PU in it, it actually lasted less then 5 thousand miles or not even at all, really u$ele$$ $waybar.
Thank you for your help I got a stiff stabilizer bar now, let's see how long the PU will hold. Stiffness compared but pushing your thumb in it, PU more then twice as stiff. I really wonder what that yellow stuff has been made of.
Topic solved!