Every Nissan car I've ever owned has reported 1000lbs maximum towing weight including passengers/cargo, as others have said consult the owners manual for confirmation
the loads may have changed for the Q50.
The Federal Motor Vehicle Safety Standards (US & Canada) state that the GVWR (Gross Vehicle Weight Rating) and GAWR (Gross Axle Weight Rating) be posted on FMVSS label on the B pillar next to the door latch.
GVWR - maximum total combined weight of the unloaded vehicle, passengers, luggage, hitch, trailer tongue load and any other optional equipment.
GAWR - maximum weight (load) limit specified for the front or rear axle.
Curb Weight - vehicle weight including: standard and optional equipment, fluids, emergency tools, and spare tire assembly. This weight does not include passengers and cargo.
Using a 2018 RS AWD as an example:
Curb Weight = 3,993 lbs
GVWR = 5,159 lbs
GAWR = Front - 2646 lbs Rear - 2546 lbs
Vehicle Capacity Limit - This is the maximum combined weight of occupants and cargo that can be loaded into the vehicle. If the vehicle is used to tow a trailer, the trailer tongue weight must be included as part of the cargo load. This information is located on the Tire and Loading Information label next to the FMVSS label.
If you subtract the Curb Weight from the GVWR, you would expect this to be the Vehicle Capacity Limit.
5,159 - 3,993 = 1,166 lbs
However the Tire and Loading Information label on the 2018 RS AWD states a Vehicle Capacity Limit of 900 lbs. This more conservative weight limit is the one that matters.
I think the important thing to consider is that all the definitions of these acronyms (GVW, GVWR, GAWR, GCWR) are standard government boilerplate and do not take into consideration specific manufacturer's designated limitations. I would expect the manufacturer's recommendations to supersede these numbers.
The standard GVWR definition includes hitch and trailer tongue load and that number would lead you to believe that one can tow a trailer if the Vehicle Capacity Limit isn't exceeded. The fact that the Owner's Manual specifically states not to tow a trailer with a Q50 would take precedence in any warranty issues that may occur due to engine and/or transmission damages from towing.
So as the OP said: "Who's ballsy enough to tow with this beast?". Not me. The car was not designed to tow and I believe them.