You can always bag your current trailer. Granted, you probably can't get it to lay flat like those pictured, but you can drop it significantly. Only around $450 per axle and a heap of fabrication to get them installed.
I honestly can't see that being a huge benefit for most street cars. There are some race cars I've seen that could have benefited form that arrangement, but these days, so many guys use enclosed trailers, I'm surprised they put this much effort into an open unit.