Ok this is a bit of an odd one..the rear bumper has plastic fixings on the inside of the side cheeks that slide onto brackets on the rear wings. problem is EKTA show these side pieces as part of the bumper and both of mine are broken.
If you have a broken rear bumper with good side cheeks, I could cut them off and bond them onto my bumper. (BTW my bumper is for a rallye with the rare removable tow hitch, so the chances of finding another is..impossible)