In Australia. Have 2010 Superb Elegance 2.0 TDi DSG Wagon with 120,000kms. Had it from new and never towed with it yet.  My Mazda MX-5 is about to cease to be a road and track car and become only a track car so I need to start towing it to events.  The trailer and car will be 1,500kg, or less if I go with a dolly trailer.

 

I know the motor and the car will happily tow that weight, but how will the DSG box fare?

DSG will be fine, I'm more worried about the ball weight and your 'lowered sports suspension'.

don't know about it'll be fine, 40 c and extra weight,

Maximum towing load for the 170 DSG is 1800 kg according to the manual so your trailer should be ok. I'd take note of peterposh's comment on temperatures though. If you have access to diagnostics, it'd be good to keep an eye on the DSG temperature while you're on the road. Something like Torque or OBDEleven on your phone with a bluetooth interface.

 

Maximum tongue weight with standard suspension is 80 kg so you'll need to keep an eye on how the trailer is loaded. With your lowered suspension if it's aftermarket you may have to look at some sort of towing assist device on the rear suspension to prevent it bottoming out.

I tow 1.5 tonne caravan here in France and have never had any problem at all. Mine is a manual so I cant comment on that but as a tow car it is in a league of its own.

The suspension was a factory sports option which came with 18s, about an inch lower, and stiffer springs.  I reckon the latter two cancel each other out and in any case I should be under 80kg towball weight.

 

How would I get access to diagnostics in order to monitor DSG temps, and at what temp should I be giving it a rest?