Edmunds says the Honda Fit has a curb weight of just over 2300lb...but Honda does not currently recommend any models for flat towing that I know of. Here's a reliable list of flat towable cars:
http://www.motorhome.com/download-dinghy-guides/
But first, the Sprinter based Citation line has a Class III hitch receiver (5000lb capacity), however the towing capacity has less than 5000lb available if you load the RV at or near the GVWR (max weight that can be carried upon the RV's tires).
GCWR (15,250) minus GVWR (11,030lb) equals dedicated towing capacity = 4,220lb.
And these Eurovan based RV's have a rather low OCCC (amount of "stuff" and people that can be carried within the RV) to take you to GVWR. The OCCC is on an orange decal by/on the passenger door.
Second, brakes are not required on toad cars in many places (check your local laws)...some jurisdiction's laws simply say the set-up must stop within XX feet. And this is rarely an item that is checked by authorities, until there is an accident.
But the reality is that brakes are smart for driving manners of the RV, and are obviously safer than without. Hope you get a supplimental brake system on the toad.
Best luck