I installed my fantastic fan with no problems at all. No I didn't have to enlarge the hole, just a tad of trimming was all that was needed. I did order the airstream curved interior bezel, and that needed a bit of trimming with my dremel. For me the worry was the electrical. I wasnt' sure if my 12v/110 system with no inverter was gonna work. I just wired it to the hot
12v circuit, and can switch it off at the fan or the toggle 110/12v switch on the ceiling. Seems to work fine on the 12 v. Not gonna worry about using it on 110. Mike