Below I have an image of a bookmobile that I am creating in illustrator...
The main goal of this is to get the gradient shape inside the perimeters of the bus and not including the wheels. When I try to make a clipping mask it says, "The top object is very complex, and may fail the document to print or preview if used as a mask. Do you want to make it a mask anyway?". I click yes but the bus and gradient shape both disappear. Since the bus is made up of many different shapes, I attempted to ungroup them but to no avail have I been able to get this to work. What would be the best solution in this situation?