Wanting to reduce noise, my search of sources in and around our FR3 cockpit are, the "doghouse" inspection revealed a weatherstripping so poorly sealed that hot air and sound would blast into the cockpit.
If you complain about your AC not working, this was a huge factor for comfort while driving. If you complain about excess noise, this was a huge factor for comfort while trying to speak to a passenger.
Using real rubber expanding weatherstrip, filling the poorly formed doghouse cover to floor channel fit can be a HUGE benefit if your FR3 is like our 2014 DS25.
Once this area is properly sealed, you will then notice other sources of sound.
Side windows in our FR3 then became one of the loudest sources of noise. Inspecting the windows only served to instill resignation that short of sealing the entire window with sound deadening, there was little else effective enough to be worth blocking the side mirror view. If I wanted to throw $$$ at the problem, there are double insulated windows at a cost that I don't have the courage to investigate.(non-wealthy human!)
Others who have walked this path have reported the windshield on FR3s' are not well sealed from FR, that removal/re-seal with lots of tubes of black sealer can make a big difference.
FR3s' are built to a price point, results of your noise reductions efforts may vary.
In the end, a set of BOSE(and others) noise cancelling headphones are your friend. You can wear them in comfort for hours, speaking to each other with the built in microphones.
Noise can induce fatigue more quickly than almost any other factor while driving, its a useful tactic to allow for a more alert driving experience.