[aerohead]

It would be really helpful to see the scale of your trailer in relation to the Metro,as Cd posted with his "Flea" integrated trailer (which by the way looks pretty damn good to me!).---------------------

And also looking at Cd's image,consider complete,movable gap-fillers to close the void between car and trailer.I never got to do this with the 2-wheel trailer at all,and with the 1-wheel trailer,I had only enough time to cobble up a panel for the top.-----------------------------

With respect to weight,my 2-wheeler and cargo added 1,300-lbs to the CRX and mpg dropped from 52,to 50-mpg.There was also no "bottom" on the 2-wheeler,so I suspect I lost some mpg potential there also.------------------------------------

With the 1-wheeler,I ran it virtually empty.At around 250-lbs and no side or bottom gap-fillers,I pulled 48-mpg across Texas,New Mexico,and Colorado,at speeds up to 80-mph and mountain passes as high as 10,600-ft ( Vail Pass ).Note: unbeknownst to me,I had two carburetor hoses completely burned through and engine ran rich ( you can see the black soot from the tailpipe on the front side of the trailer ),so I don't actually know how well or not the trailer might have done with good vacuum lines.Hope to repeat experiment one day.I hope for alot of things!----------------------------

Lets see a car/trailer image,then we can better advise.----------------------

I suspect you could improve flat-land mpg with the trailer and I'd love to see you do it.It's one way to create the ridiculously long tail the air likes so much ( see my photo=shopped Honda Insight micro-RV for a chuckle!).