After searching the web for pictures, and ask some questions, I figgered out that the old type MX5 seat is way shorter, and should fit.
Lucky I find a cool guy that wants to swap my seats for the older type MX5 that should fit.
On this picture you can see the seats that I had, and I swapped them for the one in the middle:
The difference in the hight can be see now very clearly!
I put them in the car, and they fit! a shame I didn't buy this type earlier....
