2007 Allure 470 - I had difficulties finding the front tank drain valve - the drain showed to be in the drivers bay compartment on the drawings, but in reality it was located near the tank which is just behind the entry step on the passenger side - had to climb under the front passenger side to find the quarter turn valve.
I have wet tank, and primary tank drains in my middle compartment where the tanks are located, and I have two more drains in the engine compartment (total 5). One in the engine compartment is for the suspension system, the other is for the rear pneumatic brake tank.
Hope this helps,
Edit - pics attached. The drain valves have the yellow handles.
Towr: 2007 Country Coach Allure 470 - 37 Sunset Bay Cummins 400 ISL
Toad: 2007 Jeep Grand Cherokee (yes, it has a Hemi)