i,m not sure of your year but i googled r36 passat tow capacity and got this.
https://www.google.com/search?rlz=1C...sclient=psy-ab
and
https://www.carsguide.com.au/volkswa...-capacity/2009
understand that unbraked is with NO brake assist for trailer, so this limits you to 750kg
if you have have electric or hydraulic brakes then the tow capacity is greatly increased. but i quickly looked at those numbers and they look to match or close to your caravan.
the 2009 r36 has a maximum braked capacity of 2200kg.(you install and electric brake controller in the car) .
if your van is 1400kg , your well under the maximum limit.