I've just come back from holiday and towed my caravan with my Superb iV from Glasgow to Silverdale, then Keswick, then back to Glasgow. Having previously towed with the 2.0 turbo diesel Superb, I wasn't sure what to expect. But I have to say I was pleasantly surprised. I got it fully charged before leaving, had it on hybrid and in 'B' mode on the DSG box, and it handled the journey no problem. No overheating, 30+ to the gallon even when pulling just on petrol and handled all sorts of terrain from Motorways to hills to very tight and windy country roads.
I have the factory fitted tow-bar so maybe that helps.