Trunk fan for dogs

The car is air-conditioned, but the cool air does not seem to move much to the back of the car.Given that we drive around with dogs in the trunk in summer, I designed this holder to move the air from the front to the back of the car. What you need?The model has been designed for a grid in between the backseats and trunk (if you don't have that, you will have to design your own mounting plate, step files are attached)140mm PC fan, I bought the TL-C14C by THERMALRIGHT which were the cheapest ones available to me. Note: Think of how to power the fans before buying, I recommend a 12V fan, because the cigarette lighter port outputs 12V2x heat set inserts M3x5x4 (5mm width, 4mm length), for example these (any that look similar to the linked ones and have the specified dimensions should be good)2x 20mm M3 screws (not sure about the exact length, I might have used 16mm)Some zip ties for mountingSome way to power the 12V fans, I will explain my solution belowFor mounting the fan to the prin