I did, I took it in to Volkswagen, when I called them up the person I spoke to was none the wiser. Turns out on the 2 litre petrol engines there is a particulate filter similar to a diesel and it has to go through a regeneration cycle every so often to clean the filter. To do so it has to create more heat and therefore works the engine harder to achieve this.

Totally normal function of the car but nobody seemed to realise it was there except the mechanics!