Been playing around with this forabout4 months now and this is what I came up with. The fans although not waterproof (still working on that, and may have a source soon) are definitely water resistant. I can turn them on and spray them with a water bottle directly on the fan and they keep working. As far as the dust and dirt, I have 2 miles of dirt roadbefore I get to the highway and so far so good. I washed it the other day and hosed off any dust so not sure if the dust will ever have any affect on these fans. As far as the vibration I guess only time will tell. Been running this setup for about 4 months now, mostly in the garage because of the weather, andit looks good so far.There is also a temp switch which can be set between 180f and 250f that turn the fans on automatically. The switch will also allow you to turn the fans on and off manually.
Quigley

Added some more pictures. There is a before and after picture of where the temp probe goes into where the pressure switch is located. By using a tee the pressure switch can be retained. The switch that controls the fan is located where ever you want. You decide where to put the switch.
Quigley