Could a oil film come out of the condensate drain line
Lay a piece of clean paper (printer paper is good) under where the spot should appear ... when you get a sample of what it's doing the take it to the dealer ... I suspect your 2015 is still under warranty so for heaven's sake don't attempt anything yourself. BTW ... keep the paper as evidence in case the Dealer tries to minimize the problem and the problem worsens Good Luck
Search Toyota Camry Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Toyota Camry Experts