Hi everybody, just to let you know I have sorted the original "Restricted Performance" issue caused by fitting an aftermarket rear light cluster. I decided to retain the old body which the vehicle accepted, and replaced the damaged lens.
I must say this was not an easy project, and the use of a heat gun to "melt" the adhesive that bonded the old lens was a failure as the melting point of this was far higher than the surrounding plastic , so had to resort to brute force and ignorance and break away by hand and trim with a Dremel grinding tool.

To add to this my lens border is Grey and could only purchase a Black bordered lens, so had to spray to match. All in all a very satisfactory result but not sure I would want to tackle again .

Just for the record I have a new "Restricted Performance" message with the Red triangle of doom staring at me which relates to code :- P1247 Turbocharger Boost Pressure low.
If I park the vehicle, switch off then restart the error is cleared and only to return on the next journey particularly if I have to use extra acceleration .
Have any other members had this ? and if so how did you sort please.

You can get restricted performance from a split inlet manifold. Not sure if it would throw up that error code, however. Otherwise could be sticking turbo vane actuator. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Thank`s for that, I`m hoping that is the worse case sinario. From what I have read this would normally be accompanied with a rough idle and mine is very smooth, with a bit of luck it may be yet another silly little RR glitch but would be nice to know if any members have experienced the same.