I'm afraid that you'll have to do really massive pick-and -shovel type mods to get the air cleaned up enough for the smaller mods to have a chance to function.
A friend recently got a 22-ft APEX trailer which he pulls behind a new 4RUNNER.Last weekend he hosted a star party out in New Mexico and returned 12.5 mpg on a 270-mile round trip.About 1/2 solo mpg.
I got a 'free' but very expensive rooftop fairing with side panels off a Peterbilt tractor.We're going to try to chop and channel it to fit the Toyota's roof rack.
Then go after the hard corners on the trailers side leading edges.
I feel like this will be a 'minimum' effort to see any meaningful improvement.
You'll never see a vitamin tablet or suppository which looks like these trailers.And for good reason.
They'd tear you a new one,just like they're doing at the gas pump.
