ebacherville,
when the shape of the whole car is perfected/finished, there is a window of opportunity to decide to redo all the new panels in metal. That is an excuse to get this:
http://ww2.harborfreight.com/cpi/cta...emnumber=95359
Not as fancy as this:
http://www.metalcrafttools.com/englishwheel.html
But much cheaper (was 199 on sale in springfield MA store)
It works like this