I've not heard of them scrapping the TDI idea, unless they can't get enough cars built there's no real reason not to race the TDI in the BTCC, it's more development time = more data. Also add to that the TDI will be very useful in the UK, our tracks are twisiter so the torque will be useful. Although tyres haven't been dealt with, will it be a competitive package with Dunlops? Supposedly the TDI isn't as kind on its tyres as the petrol version. That's where the twisty bit comes in, more tyre wear. Thruxton could be interesting.
Then again, there's a very important rule in the BTCC - the only way to tell if a car will be on the grid at Brands is the media day. That's when the actual entry list is confirmed and there's no assurances they will turn up then. I can't remember when it is, I think it's next month and it will be at Rockingham.