I don't build, nor do I desire many replicas, but that being said, I understand how some folks do.
Not trying to hijack the thread....but.......I built these cars using very simple tools.
Got a desktop computer & used Google image to screen capture or scanned a photo into Microsoft Paint.
This software has been around since the mouse. :) Anybody using a Photo-Shop program could do MUCH better I'm sure.
This is the only software I use.
I tweak it, reshape it, edit it then size it with a few test prints on plain paper.
I print it on decal paper (either white or clear) using a 7 year old, $50 HP Photosmart inkjet printer.
Spray the printed decals with Ace Hardware clear enamel rattle can & apply using any decal set liquid available at any hobby shop.
I usually coat with some "Future". (Sometimes clear coat, (but not often anymore)
The great thing is, you have a a permanent file & can print as many copies as you want.
I usually print two at a time, just in case. :?
As for durability........................
The #10 ASA car & the sixty-six ninety-nine mod survived Harry's Showdown, no sweat. :banana-dance:
Pretty sure most anybody (with some time & patience) could do this for very little money.
I'm close to 72 years old & figured out how-to..............................................No offense to old guys. :|