When making a car cake, and you want to enlarge the picture for carving purposes, how do you know how big to make it, in order to get the servings needed. For instance, If I need to serve 30 people, how much do I enlarge the picture for carving.?

Some people say a 9X13 serves 24 people..
If you carve a 9X13 can pan into a car - it could serve about 20 or so.

I would put play with the picture size to make it as large as it will print on the paper..
And carve from there? GL

U might have to use a bigger cake pan to serve 30 people or bake 2 9x13 and carve from there
Picture printed on two pieces of paper