My new petrol 1.4 TSI DSG smells of burning rubber

My Octavia Estate 1.4 TSI DSG is not absolutely new - it's now a year old - but it has always done this.

I live near the top of a long hill. If I come home up the hill, when I arrive there is a strong smell of burning rubber that appears to come from the LHS at the rear (ie from somewhere near the exhaust box). I've tried checking the temperature of the discs (all OK, and the brakes obviously haven't been used). The last bit of the exhaust is warm rather than hot. No doubt I ought to grovel underneath to locate where there's something hot, but so far I haven't been able to.

More often I come home the other way - flat and then a slight downhill - and there's no smell at all. The uphill route is about 3 miles long, and it's not all that steep, though it has a number of quite sharp bends. The automatic box does it in 4, 5 and 6 usually, and the engine doesn't seem to be working very hard.

I'm puzzled by this as it is quite a strong smell of burning. But it has neither got worse nor gone away, and the car's under warranty. I bought it new. I'm not really quite sure if I've given a full description of the engine - the purchase papers described it as "Green Tech" too, with a load of other numbers and abbreviations, but I expect that's all just advertising speak for the 21st Century.

Has anyone else seen the same thing?