[Teutonic]

Gentlemen, the smell comes from the two pieces of material that are placed under the vehicle and covers the bottom to protect the cables, reduce the noise and improve the aerodinamics.
Under the car, they mounted two big pieces that are made of some material that is covered with some plushy material. When it gets soaked it takes some time to dry out. If the vehicle doesnt dry or wont get ventilation, it will smell until it dries out, especially in a closed garage.
Go, wash the car and next day in the morning put your fingers and touch the material. You will get the same smell.
If the car sits outside in the sun or has time to dry prior to parking it in the garage, there will be no smell.

In regards with the AC it is a good ideea to turn it off sometimes and let the normal air ventilation to run and dry out the condensation.