So I am making a wedding cake for my cousin and have a three hour car ride to deliver it. I decided to just do the basic part of the decorating and then finish when I arrive. So I baked, filled and frosted the cakes and then covered them in white fondant and airbrushed them gold. I loaded them in my vehicle (unstacked) and drove to my destination. When I arrived the fondant had huge air bubbles and looked saggy (real saggy) around the bottom but only on one side. As far as I can tell the cake looks in tact, just the fondant is messed up. I’m mortified and embarrassed to even let anyone see this cake but I really have no choice! I have made many cakes and brought them to this same location without any problems so I don’t understand what happened this time. My truck was not to hot so I know that wasn’t a problem. Has this happened to any of you? 

Also I’ve been decorating cakes for 10+ years and this is my first cake disaster. 

i box all my cakes and deliver them cold right outa the fridge -- it stops all the action -- if it's gonna go to pot i'm gonna see it first -- by the time it chills in there -- the fondant has set up and all is well -- i always work with cold cake --

so i don't know if yours were cold and boxed or not although it doesn't sound like it and that is an idea for you for going forward -- did the sun hit the cake in the car? there coulda been an air bubble too -- and ka-boom! 

i hate that happened -- cake can be so unpredictable sometimes -- i mean look at you -- ten years into this and sucha crazy occurrence --

best to you

Ooohh how miserable for you.  I've not had that much experience with fondant to know sny way you can repair that.  Just hope the decorations helped to hide some of the problem areas.   As K8 said, fondant can be a problem.  I'm thinking weather had some to do w/it.  Did you climb elevation?  That also probably cause some of the problem. 

air bubbles!

I've had this happen to me with fondant and once with buttercream. I finally learned from Cake Central that if you take your cake out of the fridge you need to poke with a skewer or toothpick little holes along the bottom and/or sides of the cake to let the air escape as it warms up. They also call it a blowout.  you can always poke the fondant with a small needle to let the air out and then resmooth and trim it. That seems like a lot of air in there.

Trapped air pockets! I hate this has happened to you, but maybe our advice/experiences can be of help to prevent it from happening again in the future. I take a cake pop stick and insert it completely down the center of the cake as if to create a "chimney" for any trapped air to escape while the cake settles.