Hot Wheels Cake / And learn from my mistakes!

My youngest son was turning 4 years old and wanted a Hot Wheels cake for his birthday party.  And Normally when I am making a cake with something made from Gumpaste I make it at least 4-5 days before the cake is due and I make 2 of everything in case something breaks (and most of the time one does!)
Well my mistakes were that I didn't make the gumpaste items until 1 1/2 days before the cake needed to be done and only make one set of the gumpaste items.  What I was making was loops that the hot wheels tracks always have and I was going to have the loops go from the bottom to the top of the bottom tier and from there up to the top tier.
So of course it was super humid here in CT and the gumpaste items didn't dry.  And I tried a trick of putting them in the oven at 200 degrees and the flame hoop was just fine, but not the loops. They ended up breaking.  And since I didn't have two I had no choice, but to do with out!  Luckily it was for my son and of course he still loved the cake.  I just feel bad because it could have looked even better!
So what do we learn!  Always give your gumpaste items extra days to dry!  At least 2 days extra.  And ALWAYS make two in case one breaks.