yikes...
average jetski 500-750 pounds. add another couple hundred for the trailer and you are up to 1/3rd the weight of the vehicle...
i would pick up an old beater truck rather than put the wear and tear on my brand new car.
The latter point is fair, but the % of weight compared to the tow vehicle is not. Small SUVs regularly have 3500 lbs tow capacity while barely being heavier than that themselves. Big Dualies regularly to 10k and up in tow capacity and actually weigh less than that. Big rigs go 80k gross combined vehicle weight while weighing maybe 20k or less.
It's a matter of how well cooled the engine and tranny are, proper braking systems, tires and suspension systems, and sway control - especially as the weights climb.
A thousand pounds or less is next to nothing, in terms of towing.
JMHO - but based on doing a lot of towing over the years.
I'd add that aero is a big part of it as well. A jet ski is pretty low profile, so you dont have a barn door back there either. Shouldnt pose much of a problem. Not sure of the load ratings, but a lot of Porsche guys drag tire trailers behind Boxsters and the like to track. Four 18s and steel trail, far worse aero profile, is likely around 3-400#s. Those guys have no problem whatsoever.A thousand pounds or less is next to nothing, in terms of towing.
JMHO - but based on doing a lot of towing over the years.