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