Use a DPDT relay, its what I am using.
There are 8 pins on it. A pair to activate the relay, 2 pairs power in, and the last pair for power out.
I dont know how their device works, but the actuators I'm using, you give it power in one direction for it to push out, flip the wires or the power's direction and it retracts. I am using one power source, but 2 cables coming out from the + wire and 2 to -(grnd). The first pair of wires are wired + then -, then so the polarity is flipped, the second set is wired - then +. When the relay is off or in its normal position, it will have + - for its power source, then when the relay gets power the turn on or make the switch, it will have - + for its power source.
I am using the fan to get power to the relay to activate only when the car is on.
If this is confusing, I will draw you a diagram shortly. I have been told I explain things bad, everything goes on so fast in my head and I understand it but once it comes out it might not make sense to the outside world.