We have spent a lot of time thinking about the roof design! This is because between us we have owned a sports car with no roof or windscreen (the Fisher Fury R1) and a S1 Lotus Elise with a very basic cloth roof. We also have a Eunos Roadster with a soft-top that is quite hard to open and close from inside the car and has two latches that can be hard to reach and use. The soft top MX-5 ND is a joy to operate though, with a single, central catch. We have also spent a lot of time in an MX-5 RF, which features an electric folding mechanism.
These kind of cars are simply not as much fun with the roof up but, sometimes they are left outside or the weather is not conducive to 'roof down' driving. For this reason our sports EV will feature a fully waterproof roof. The focus is very much on light-weight and practicality but, the current design assumes you have to be outside the OSSEV® to fit it or remove it.
The initial sports EV design is based on frameless door windows and an integral roll bar (which improves safety) with rear-buttresses (like the Lotus Elise pictured here). This design allows a removeable roof (in one or two section) to be stored securely in the car. This means that there will also be a rear window that can raised or lowered.