That is a dumb but easy to make mistake. I think it should be noted that even well maintained brake systems can find a way to corrode and drip - not like yours, but drip nonetheless. That's why we look for it. I say this because I have seen many cars stacked without any drip pans or barriers. Maybe your disaster can save someone else. It might be painful but pictures would be worthwhile. Sorry for your disaster and gold no one was hurt.
The car was restored over 5 years ago - and I have owned it for 1 year. I never noticed a single drip up front. Now under the engine is another story.
During the Winter is probably failed and started to drip - first in the steering rack cover pan then into the drip tray (2X4 frame with Masonite bottoms and caulked all around). It then puddle to a corner of the drip pan where it slowly ate away the caulk material and found its way to the car below.
I do hope that this saves someone some future mishap.
See you at Route 66 - hopefully in the car that leaked - cheers!