Hi all, having just read all these posts and picking my car (420r) up from Silverstone Caterham in the wet after its mot and noticing wheel spin from only the one wheel I have done the wheel turn test and described above and on turning one wheel the second is stationary and sounds like I have the same problem as many here. Question if I continue to use the car until I get it back to the dealer am I causing more damage and expense or is it just working as an open diff. If they dealer won't sort it is the diff easy enough to remove and I will look of change to the spc diff. Great topic and hugely helpful