Kids 3D car projects needs a new list to work with...

This is an interesting 3D Car drive project for kids. Based on an educational project which caught my eye, last year (also featured in “Hello World” magazine). Link to that UK article below is how it works and coded example:

I am adapting it for SNAP! and it does seem to work works fine as a proper listing. I have simply replaced the many ‘costume’ sprite angles with a simple ‘LIST’ of angles’. And it does! it works well, better than expected in my own tests on SCRATCH (1 and 2). Won't work in 3.

But - trying to replicate that here on SNAP! - I am stuck on a simple list function. (partially working, test project can be seen here):

Feel free to suggest a solution which my coding club kids could adopt easily. What am I missing here?

Thanks Philip

For left arrow pressed, you have ((costume #) - (-1)) which is the same as ((costume #) + (1)).

The direction of the sprite does change, but the costume doesn't because of the rotation style, which can be changed with the three buttons between the category buttons and sprite icon near the top.

Here is a simplified version of the project:

Costumes can be named #angle and change accordingly to "direction" attribute, e.g. #0, #90. "#" to avoid confusion between costume index and name.
If You want to use the index, take into account that costume[0] is a special kind, called Turtle (actually an arrow). Also, setting -1, 0 or nonexistent costume "dresses" a Turtle.
Also, x position after move should be affected by perspective to avoid slide effect.

Thanks Dardoro, you've solved a couple of problems there and its easy enough for kids to follow. And you have also solved the problem of costume [0] which was not obvious to me either, as it is now. A good learning curve and I shall be adopting that solution with more costumes to give a smoother 3D (rotate) experience. Thanks for that input, solved a big problem for me as I could not see past list variable. This is now playable and I can move on to the next stage.. Thanks.

You're welcome.