2010 Mazda3 are the same as previous generation so there is strong possibility it would, Although I bet nobody tried it yet.
I have 2010 Tripoint Engineering MazdaSpeed3 swaybar on my 2010 Mazda5 and it fits.
I know, I'm working with the hosting company now. It's not everyone which is making it very difficult to figure out. Try another computer is all I can say at this time.
It works! Thanks! I didn't know you had information on the sway bars at the top of this thread though. This is definitely my next mod in the next few months, after I get my new shocks/struts/springs in!