/\/\/\/\/\It is sad to see it come to that with a customer just because of an idiot Service Manager.
I spent 9 years on the line as a Ford Tech and 3 years as an advisor. I worked at 3 different dealerships over that time and was fortunate to always have been at dealerships that were reasonable regarding modifications. (It helped that I was modding cars for customers- sometimes for the Sales and Service Managers friends!)
I've seen cars that were properly modded and drive for miles without incident and seen cars that were poorly modded and have had nothing but issues. The manufacturer obviously can't be responsible for every modded vehicle out on the road, how the work was done, or how the vehicle is being driven so the warranty is written to protect the manufacturer from the hand full of idiots that ruin it for everyone else. The language used to be that if the dealership determined that the modification was the cause of the part failure that the repair would not be warrantied. Most dealerships are given the latitude to make the judgement call on that but can refer to a factory rep if needed.
I've only seen one time in those 12 years that a full factory warranty was voided and in that case it should have been- the vehicle was unsafely modified and should not have even been on the road let alone the Manufacturer pay for the part failure.
....sorry... I'm rambling... its been a long day... and its only Tuesday.