As the subject is already telling,

i am looking for a rear diffusor to make it fit on my dax rush.

I want to close the floor of the car anyways and doing this, i thought i might directly mount a diffusor who does the job as i like the look.
Does anoybody have one for sale?

Male one... dead easy

As coozer says - make one!

Sheets of 1mm thick Aluminium pair of tin snips and some rivets. An evening or two should have it sorted.