Just opened the boot on my Zed ( not used it for ages )
and saw the tow eye floating around in the back , I remembered it was used at Silverstone last ( you need one inserted on the track time laps )
Also remembered that it would only force in half a turn as the threads in the car were different to the ones on the tow eye. A few others had the same problem on the day ..
Just measured the tow eye thread (which is 16mm X 2.00 ) found a tap and re-threaded the front mount..
It may be as well to check yours actually does screw in on the front fitting , or it's to late if you have an emergency and need it