Just got my Fender Usa pbass fretless 2 weeks ago. Man, I hate flatwounds but I guess they are best for my neck. Any Advice on care (cleaning/maintaining) for the neck as well as those damn flatwounds?

Try some GHS Brite Flats. They might feel/sound better to you.

You may also want to take a look at GHS Pressurewound strings. They take regular round wound strings and compress the outer winding -- to "smooth" it out. I used that on my P bass fretless for years. It's not quite as bright as a round wound string, but MUCH better than flatwound.

Hope this helps.

TI-Flats-soung good
TI-Jazz-Rounds-cross between flats and rounds.
Also Always wipe down string and fingerboard after
playing. Simple ,yes but will add life of string. and will keep unwanted gunk from building on fingerboard.
FUNK GOOD
GUNK BAD