Looking around at folding bikes recently and it struck me that most folders have a lot of welds and complex bits made out of tubing compared to a trad diamond frame.
It is the one type of bike that could really be improved by construction in carbon fibre. Imagine if each part of the folding frame could be made in any shape, without having to use tubes or even be symetrical. Once you have the moulds, then one shape of carbon is as easy to make as another. You could radically lighten a compact folder such as the bromton.