I have a bit of towing expiriance with an open trailer, here is what I have found, our trailer is a homemade 100inchesx100inches an we can fit 3 bikes on it, it is a major PITA when you come up to construction and have to try and get through with a car that is 80 inches wide and a trailer that sticks out a foot at least on each side. We made ours and have 13 inch tires on it and have not had a problem with it, even with three bikes on it. We have had a near bearing failure in ohio(thanks to the guy at partsource if he is on here) and that has been about it. the trailer has around 20,000 kms on it now and is still going strong. it has been "track tested" to around 100mph with 2 bikes on it(fastest my bike has ever gone was on a trailer

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We have been thinking of making another one for the upcoming season what we have planned so far would be about 100 to 120 long by 90-96 wide with a single axle and as light as possible. My buddy also has condor stands that are mounted to the trailer, so that makes it much easier to load and unload too. I think that I have a pick of it in one of my galleries
As for pulling with a civic, no problem, most Hondas are rated at 1500 pounds and if they are a 5 speed they will pull more than that

you just have to watch slowing down they dont stop as well with an extra 900-1000 pounds out back. Hope that some of this helped.