I made this Motorcycle cake a while back for a bride looking to surprise her groom with a replica of his motorcycle. It serves 50+.
First, my husband cut a piece of wood that was the shape of the motorcycle body. I wrapped it in foil them placed the cake on top. Two short wood dowels were screwed into the board and the cake base to suspend so that it was suspended in the air like a real motorcycle body.
The entire body of the bike is cake, iced with buttercream, then covered in fondant. The wheels are 6″ foam pieces iced with buttercream, then covered in fondant. The handle-bars are wood dowels cut and hot glued together, then covered in fondant. The headlight is a cone shaped piece of foam, glued to a square piece of foam, iced in buttercream and covered in fondant. The skull paint job is Wilton food colors, mixed with a drop or two of water, and painted on with a paint brush. All of the engine parts, pipes, etc. on the side of the bike are fondant. The shine on the cake was made by mixing Wilton pearl dust(white or silver) with vodka and brushing it on the fondant with a paintbrush.
Estimated amount of hours my husband and I spent on this? About 20-25 hours(not including cake baking time).