Here is a 6" top and 8" bottom tier. This cake had to travel a few hours in the car and shifted a little bit. Both layers are yellow cake with chocolate buttercream, covered in MMF. The decorations are also MMF with green buttercream for the grass. If I could do this cake over, I would have used a 10" bottom tier so I'd have more room for the cars to sit. I had more cars to put on, but the road was too narrow (about 1 inch of workable space for the cars). That was pretty limiting for me, but the cake was a hit and tasted wonderful!!!!!!!