Does anyone in here have an opinion on the Green Zone folding tandem bikes? I'm looking for a full size tandem for casual riding. My wife and I travel some and would love to carry it on the back of our car. I haven't seen anything other than the small wheeled Amazon bikes. I've seen a couple Green Zone folding tandems that appear to be full size bikes. I know they're no longer manufactured but I have seen a coule used ones out there for sale. Wondering if anyone has any input on these.