Re: cant booleen out wheel wells
Flip the normals on the box, they are facing inwards and should not be for the boolean functions to work.
A quick way to check for this is to set all surfaces to 1S (one-sided) - you'll soon see which normals are wrong. Also, press 'n' in the 3d window and check you can see all the pink line coming out of each surface. If you see only a pink dot, you need to flip the normal.