Weight would still very much be an issue with a locost frame or design. Their entire frame is 3/4" and 1/2" tubing, providing hardly more than a scaffolding to hold everything up with as little weight as possible, making it a fraction of the weight of a common locost chassis. Why they still used a car engine (a 2.5 subaru at that), aside from cost (with only 190hp on tap standard), is entirely beyond me, though. That, and I'm not a fan of their single-shear front a-arms on those long bolts, but I suppose it's less of an issue with its weight, low cornering forces (high CoG), and skinny tires that gain camber like crazy, and the fact it's made to spend much of its time in the air instead.
But I do love that it exists, and flies/drives as well as it seems to, though I'd personally swap in a motorcycle powerplant (50% less weight with an integrated transmission? yes please) and rearrange their suspension some. Parachute-assisted flying seems like such a logical, cheaper, easier move than a full blown winged/multi-engined car, I'd love to see where they take it from here.