Welcome to the Cake Decorators Q&A

Should I place a cake card under the tiers of the fruit cake or should I just dowel
under the layers?

Hi Vonny

If I was doing this I would place cards and dowels. Sometimes if the fruit cake is really moist it can get a bit of a wobble and start leaning. Voice of personal experience talking here, it was funny, thank goodness it was just for a friend! Better to be safe than sorry.