Starting to figure out the basic body shape. Obviously a lot of my control edges aren't in place yet (for example, the one on the bottom step or around the back door cutout).
I think those lumpy areas you have are from you wanting to model too much. For some of those shapes just use primitives and model with them. instead of having to box model everything. like for example 1/4 of a cylinder could help with the angle of the back, top part of the bus. Also, some your edges are looking tight…