You have a link to the discussion by any chance?
It's on V-Club you have to join to have access...I have copied and pasted Mirza's response....hope I am not breaking any rules here
Mirza Grebovic
Sean,
you are correct on the dive planes. The non Carbon cars don't have the fascia holes to insert them and yes there is a plastic bracket in back for the dive planes to not flex the fascia, crack the paint etc. They see significant force and the car gets close to 200mph. There is no template to cut the holes but without the bracket no point, its sonic welded to fascia.
See attached for the aero on the CT4-V Blackwing.
One thing to keep in mind is, I am seeing a lot of non carbon CT4-V Blackwings being looked at as less superior due to the aero. The CF1 adds a lot more drag, so depending on the track the CF1 cars are not always the better tool. VIR Full has a lot of high speed and on that track I would pick the non CF1 probably, Nurburgring for example is another interesting one with that massive back straight and high speeds all around.
The CF1 makes it nibbler and on many shorter tracks or high speed sweepers can lead to better lap times, but we are not talking half a second or more here. However, every tenth counts and over 15-20 laps with the V6 not running out of gas it adds up to seconds overall and that counts!
For a track toy the non CF1 car is as capable, so I hope folks don't look away from them for that reason, it has its unique aero front and rear as well to make it a weapon on the track and for those off track excursions the costs of not having a full splitter and having way more clearance to ground become a positive in my opinion as well. For less experienced track customers I always recommend the non carbon cars due to that. I personally bought the full carbon on my CT4-V Blackwing because it means a lot to me, I love the look as well because I am a bit of a rebel with an attitude and my cars need to extend that for me, but I will not lie, I don't go all out on track with my 4 sometimes because the cost of the carbon is on my mind!
This brings me to the original question, Mike Franks is right, the CF1 is a kit, and the non CF1 car has unique front splitters and unique rear spoiler since they work together. If you absolutely want carbon on your non carbon car, adding the splitter and the rear spoiler is no big deal and they will work together, you will not have the benefit of the dive planes but at least you modified the front and the rear in the right direction.
Just don't be surprised if the non carbon cars are all over your rear view mirror asking for a point by!