Rain coming into both new vehicles

we purchased 2 Toyota Quantums on the 3rd of December 2019 its only been a few days and both vehicles have rain coming inside them through rooftops and windows, we called Toyota and they said we must bring them in when its sunny, so in the meanwhile the rain must come inside the cars until it stops raining, another worry is that we recently installed a sound system which means we cant drive the cars because its raining and this might interrupt with wiring.