I would take a urethane one of course if done right.
CF is no better in this application than fiberglass unless you only care about how it looks which will deteriorate with use, not going to take any more abuse than fiberglass if made like most which are mostly FG anyway, just harder to fix, if pure CF a bit stronger but not flexible enough to matter, it will shatter if hit hard enough or just crack like fiberglass.
If building a race car within a set of rules and need to shave every once then it might matter but for a street car, even a street track car, the savings will be pretty minimal at best.
I love CF stuff, I have had lots of beautiful parts made from it and had a $1k splitter on my race vette I had to paint as the finish was crap when I received it. I was the very first to have a carbon/kevlar roof on a Scion tC, custom mounted and saved 46 lbs compared to the glass roof the car came with. I also had a custom $1800 wing element made for my last project car, just the center section, it was a work of art. I had a $300 bumper splitter because I knew it would get broken sooner or later.
Just saying this out of experience, why not fiberglass?