How to convert surfaces of the car to one single solid body on solidworks?

I am not able to convert the surfaces of the car which is drawn to solid body. Please help me with this issue because I need to run flow simulation which doesn't work without converting the drawing to solid body.

1 Answer

The surfaces need to form an enclosed volume before you can do that. If there are any openings in the enclosed volume it won't work, except perhaps as a 'thickened' surface.