I sort of know how you feel here having had the plug problem on a brand new car at just 3.5k miles... for me despair set in pretty quick having had a load of trouble in the past with my V6, especially when you just shelled out £30k+ to get a warranty and reliability. That said i have done nearly 3.5kmiles more now on the remap and plugs and all seems well in fact better than well as the car loosens up a bit. Only you can decide how much agro you can take but my feeling is you are almost there and with a clutch you might be there.Any performance car is a money sponge but without reliability its a total pain in the neck as well. dont be fooled into thinking the other mans grass is greener unless you know someone with a 335d who "hasnt" had a new turbo .....and do you think you would not want to map that anyway after about a week ??...or less. To me the S3 is a totall package of niceness and the engine is only part of the equation. change to another car and you might have a quick engine but will it have the S3 package of niceness ? that is why i bought the S3. By the way. I looked into the porker route before the S3 and yes you get 2 years warranty because they simply couldn't sell them without but after 2 years they will not want it back and their dealer prices are 5k-10k up on non dealer prices so basically you are just buying that warranty anyway. Step back, have a good think and dont let it spoil your Christmas mate.