So have now had more discussions with Mercedes UK head office, and they were of the opinion that the car should have gone straight to the West London dealership as they are an AMG specialist. Now that the car had been removed from Mercedes and taken to an independent, West London will not accept the car, as it would give them the potential financial liability which they are unwilling to accept. They then took me through 3 outcome scenarios based upon what they have seen with previous similar cases, and the best outcome was a 50% contribution from the factory if they could prove it was not down to outside interference, which would leave me with a £35k bill. Apparently there is no way they would ever increase the contribution beyond 50% and in some scenarios they would not make any contribution.
They were also insistent that it is down to the dealership to rectify the issue, they take the financial liability, not the manufacturer. Although they also stated that the engine would need to back to Germany as the manufacturer would want to see it.
They also confirmed the oil analysis on its own would not be enough to secure a contribution from the manufacturer, it would need to be stripped down. There was no confirmation around the fee West London would have imposed for them to strip down the engine.
I explained that I felt my treatment by Colindale had been appalling, and that the regularly changing storylines had let to my distrust of them, which is why I withdrew the car from the dealership. The response was that they could not comment, but they would be making this known to management, but ultimately not a lot they could do about this.
Overall Mercedes UK have washed their hands, as has the dealer. Perhaps me withdrawing the car was a wrong move, but Colindale's treatment left me with no option. Wish Mercedes UK had got involved much earlier, as perhaps then I would still be in the network, but there was no response from help was requested.
An unbelievably frustrating experience, makes you realise that although you love the product (when it works), once you have made the purchase your custom does not matter to the manufacturer. Am sure it is the same whichever car you buy. I'll be dropping in a replacement engine at the independent, stomaching the cost myself (will be cheaper than £35k), and will never buy a Mercedes again. I'll also be progressing the case with a lawyer to see if there is a cost recovery claim to be had, and if not, will be launching via the small claims court.
Thanks for all of your messages as I've gone through this journey - has kept me going through the pits of despair, but I need to bring it to a close now. For my own sanity, and my poor wifes!
If I ever get any legal recompense, I'll let you all know.
Wish you all happy and pain free motoring!