I have a reversible, 3 speed, rain sensor closing model of Fantastic Vent. Works great. With the solar panel, I can leave it run all day on low blowing in to prevent smells with a window cracked. Works great, takes the edge off on hot days. I actually have 2 with another in the bathroom. Overkill but with both running, I can move a lot of air drying the bathroom after a shower or venting the entire TC fast. If you remove the inner cover of your existing ceiling vent, there may well be 12 volt wiring already in place, there was on my TC when I installed mine. The MAXFAN cover would be nice for rain and ability to drive with the fan open driving, or just get the MAXFAN itself. Good luck!
If you want the information, here's an installation video I did installing my bathroom Fantastic Vent fan.
VIDEO: Fantastic Vent Fan Installation