Yes, window tinting is a great idea, especially if you do a lot of traveling in the southern parts of the US. Our type A came with clear windows, and the thing acted like a huge heat sink, drawing the sun in and trapping the heat as we drove down the road. Neither the dash nor the roof AC could keep up as we traveled in states south of the Mason-Dixon line. It was also nearly impossible to cool it down while parked in the afternoons.
So I bought a few rolls of very dark gray automotive tint film from J.C. Whitney. This type was cheaper and easier to apply/replace than the house stuff. I did the MH bedroom windows, the dinette windows, the salon window, the entrance door window, the double driver's side window and the copilot's double side window. Midway through our first trip, I removed the front half of the tinting film from the driver's side window and the copilot's side window, because the side visibility was too obscured by diminishing so much light. We simply could not enjoy the scenery nor the traffic conditions to either side, so we took off the film on the front half of each sliding side window, and kept the tint on the rear half of each sliding window. Much better! If you are considering doing the driver/copilot windows, consider a lighter tint or a lower density filter for just those windows.
The result is that we have reduced a significant amount of solar heat entering our space and being trapped in the coach. We have also reduced an amount of daylight on both bright and overcast days as was mentioned above, so keep that in mind. But overall, we achieved our goal of reducing heat, and it's much less work for either of our AC units to cool us down. An additional benefit, as mentioned above is the increased visual privacy during daylight hours. I would do it again in a New York minute!
Now, if you are looking to further reduce heat, don't forget your engine doghouse. We used some insulating material from J. C. Whitney, and in about two hours, we insulated the doghouse cover in our type A MH. I suspect you could do exactly the same with your type C. That has been a very satisfying improvement in reducing not only heat coming into our cockpit from the engine, but also noise reduction.