[Fixed 1.21][Bug 1.20 Steam] Car Designs window, only first page shows

If you have more than 4 car models and try to access them through the arrows on top, they only lead you to a blank page.
The only way to edit car designs beyond the first 4 is to access them through the Show Details window of the Income page of the Financial Dept.

blimey. I better fix that in the next patch…