Whenever I feel like it.
Also, here's a little something:
Meet the "Diplomat"
-snip-
Heavily wip, I'll probably remake the wheel arches.
The bodywork looks nice except for the roof; it's just too tall. In my opinion you should compensate for that by raising the cars midsection.
Also, have you considered adding some sort of interior? The insides of the cars seem rather rushed and unfinished compared to the beatiful exteriors. I'd at least like to see some different-colored panelling, some sort of dashboard and centerconsole and a steering wheel.
Racer's Rock Crawler has an animated one if I recall correctly; his racing buggy had one at least. I might attempt to create some sketches tomorrow if I have enough motivation.