Hi,
we welded a piece of flat bar steel on the frame and screwed it together with a long piece of flat aluminium, which is also fixed on the bottom of the front boot. The eye comes out of the grill. My description is terrible, but I think the pictures show it quite well.
On the back of the car we use a former seat belt, which is knotted with the crossbar, that fixes the gearbox. Maybe not the greatest solution, but it is light weight :-)
Regrards
Mecky