I read in your post that you are planning to have the guys hold the cakes. Do you mean while it's in transport? I've been doing cakes for twenty-five years and my mom did them before that and the only catastrophe that we ever had in delivery was when someone tried to hold the cake. They picked up the cake and were driving away with it and had to stop a little fast and the person could not control the cake and it went into the dash. It's much safer to set the cakes out on a flat surface like in the trunk or floorboards. Put down a clean sheet and some of that gripper stuff that comes in rolls that's meant to line shelves. Then place the cakes on that. This is how I deliver all of my cakes and haven't lost one yet. When people come to pick them up I help them put them in the car just like I told you. Have the person driving understand that they have to take off and stop very gradually and take corners slowly. I know it seems like they would be safer being held, but really they aren't. Sorry to be a little nosey about this but just had to share my experience with you. Hope everything goes well with your cake!
I agree, I would NEVER try to have someone hold a cake during a ride to deliver it. I have an SUV as well...and have the rubber gripper sheets and put them on that.