This cake was 2 tier (8", 10"). BC with fondant/gumpast ribbon accent and flowers. This order was placed 1 week before she wanted it. So, I did all these flowers on short notice. I was very pleased with the cake and thought the client was also. She left happy and paid me, but after her 1 hour drive, she called to say the cake was 'sinking'. I'm still trying to figure out exactly what happened. I used dowel supports and had not had issue with shorter deliveries in the past. I've never taken a 2 layer cake on a 1 hr road trip though. She is very upset, suggestions?