There are fenders that can be used with carbon frames. I have a version of the Race Blades for mine. I put them on before a ride if I expect rain and take them off afterwards.
http://www.rei.com/product/718392/sk...lade-xl-fender
I do have problems getting the front fender to fit on my WSD frame, so I'm actually looking for a different brand now. But there are options.
As for racks, as far as I know they are not an option for carbon frames. I make do with a large seat wedge, a top-tube bag and a handlebar bag that attaches to the handlebars with velcro strips.
As for caring for a carbon frame, I just clean it with some pink bike cleaner that I bought ages ago at the LBS. The main thing is to avoid any impact to the frame - be careful when you lean it against something, carry it, put it in or out of a car, etc.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles