Hi, I have a Yeti 1.2L DSG and tow a Puck L 230GT. The Yeti copes very well and on a reasonable run, I get low to mid 30's mpg. Because the engine is relatively small, it does not have the same torque as a deisel engine but to make up for that, the excellent DSG box changes up and down, really smoothly in order to compensate for the lower torque.
All in all, I am very happy with my combination, but of course with a 320 GT there is a bit more weight to pull.
Good luck.