A few people have asked for this thread, so here it is. I'm not a mechanic nor an engineer, but I do have a fair bit of experience in this area (on both ends of the spectrum) and am happy to share what I've learnt so far. More importantly, despite other threads existing on the topic it might be an opportune time for other TSI owners to chip in with their experiences. Please forgive my verbosity and any omissions.   Overall, I would start backwards by prefacing thus:   Despite fierce debate o