Wowee - starting to look great actually
It's been ages since I last saw this thread, so I'm pleased to see it's still going
For now I'd recommend giving the paint a little more contrast, and one or two really bright highlights along some of the edges, for instance on top of the trunk/ boot at the rear. You've hinted at this a little - but make it stronger! Be brave - it will feel wrong but look much better in the end
Only other thing that needs major work is the roll cage - the lighting on it is too uniform, and the whole thing feels a bit bright, but I'm sure you planned on working on that anyway - update us soon!