Urgent cake assembly question....

I am about to make a birthday cake for the Boy. He was 16 yesterday, and we are having a bbq in town for him tonight (a surprise!). I am thinking of making a two tiered cake (purely for serving numbers), but I don't have any dowels or cake bases to support the top cake. Do I really need it, or can i get away wihout it? Going chocolate velvet cakes, wih ganache or vienna cream filling (probably vienna, haven't got enough time for the ganache to really cool so I can whip it up), and only a poly box with ice in it for keeping it cool later. I'll be out in the car from the afternoon, and it will have to keep until later this evening. How's my chances? Oh, and hoping to give it a ganache frosting.
Eta, it is really hot here today, and my car doesnt have air cond...

Can you put a false bottom in the poly box and make some ice packs to lie on the bottom of box under the false bottom?? Iykwim!

It is going to melt if it is in a no-air-co car on a super hot day for any length of time.
You should be ok with only one top tier and no dowels etc, but I would be concerned with your cake/frosting choices, TBH. They aren't conducive to hot car sustainability.

TBH I would make 2 cakes (for quantity) then decorate one as the ceremonial go-to, then cut the other as the backup. That way you can containerise each in such a way to maximize their cooling.

Thanks everyone. In the end, the ganache didn't set. At all. It's just chocolate sauce, so I need to find a use for that :rolleyes: . The Vienna cream was fine, and I chilled the cakes sufficiently to halve them, and packed it all (the cakes and Vienna cream, not the ganache) in a cold box, to assemble on site. I also bought two filled sponges, but not a crumb of cake was eaten, so it was all for nought. I wasted my day. :cry:

Oh! They didn't eat ANY OF IT??? How many people? I'm so sorry, after all that trouble and thought and baking and decorating... That's pretty rude, imo.

I didn't end up even decorating the cakes. I was too distraught because someone had stolen my mobile phone (with all my children's photos on it). There were maybe twenty people. Maybe a few more? I really didn't pay attention to any of that. And really, I didn't care that no one had cake. But it probably was rude.

Aw, that is really awful - I read your other post but didn't connect the two. I hope you're having a much better day today, and that somehow, those pics find their way back to you.