With the fan idea, the engine has to keep idling while the blower cools the coolant and it circulates. The engine obviously is running on the cool down laps, so its no different. I don’t think there is room for the cooling carts as they are parking three cars per pit stall. I think keeping the hood down is smart. External quick connects are a good idea but the aero aspect would need to be resolved. I thought the cool down machine were always in the garage, not on the pits. There may be issues with water on the pits that could be a problem.
O.K.
They would keep the unit on the backside of pit wall like is done during the races.
The connections would be inside the cabin in My plan. The connectors are like an air hose but liquid/gas rated so they don’t leak so stray water would be minimal. Could be put on the right side of the cabin to keep clear of the driver and at some tracks they don’t run the right side Lexan and if they are it comes out easily.