Another quick update. Frustrating day really. Did all the stuff you can see here (side skirts, a-pillars, roof strips and roof) and hit save - only for Modo to crash. Luckily it crashed as soon as I hit save, as if it had started saving, I may well have corrupted the file. As it is, I only have to re-draw these bits, not the whole thing.
I have decided that it's worth backing up the scene file every day just in case the worst happens...
Anyway, here's a glimpse of where I got to before it went pop. I've got to re-do all that stuff now... Curse me for getting carried away with the modelling and forgetting to do regular saves... Grrr...