80- 93 MPH speeds average being about 87 MPH for 800km 497 miles consumption 5,6 l/100km or 43 MPG with roof box on top of the Audi A2.
https://youtu.be/BtY7zt9qR6E
Slower speeds about 90km/h avg speed 3,85 l/100km or 61MPG for 1000km
Setup can be seen in this video.