They would argue that if a car has had , lets just say, 4 owners prior to yourself they would have no way of knowing how that car has been treated or maintained over its lifetime prior to yourself....you may have kept it immaculate and get washed under the wheel arches everyweek but they don't know that and the damage may have been done long before you got the car, so no it's not your fault dani , but as with most things that are warranty based there can be so many possible solutions or arguments about the problem , at the end of the day it allways going to be difficult to convince them its not your fault, but they hold the trump card and it can cost more to argue the case than just go with the offer they make, you just need to come to an agreed deal with them that is the best you'll get.
1 owner or 1,000,000 owners, it makes NO DIFFERENCE. How it was looked after (ie washed weekly daily or once in a decade) is again irrelevant, their warranty terms don't stipulate the car has to be kept meticulously clean.
The ONLY thing that matters and what their warranty states is that it is not from prior damage....how to they check that, simple, with a paint depth gauge. A new factory fresh paint finish will have an even thickness of paint around the entire car, a resprayed area will have a (relatively) much thicker coat of paint in that area it was fixed. We are talking microns here, but paint isn't layered on by the inch, so we have to talk about microns.
If they can clearly see from the paint depth gauge that no prior repair has taken place that's it, end of discussion. This is not a "good will" claim, this is a WARRANTY claim. If my TV broke tomorrow do you think I would accept it if LG said "we'll only pay 50% because you are the 2nd owner from new even though the TV is 2 months old and you have the paperwork to prove it".
Seriously, the only way they are getting around this by calling it a "good will" is because they claim that this is actually the result of a paint defect and comes under their "3 year paint warranty, not the 12 year perforation warranty". Well how does that work? I mean the 2 go hand in hand really. If they sold a car that has no paint at all it would rust into nothingness, the same happens with a paint defect, it will cause the body underneath to rust and the paint to bubble.
Sure it may have STARTED as a paint defect, but the end result is rust, and that should be covered under the 12 year warranty. Problem is, unless you take legal action and win (therefore setting a legal precedence), they will always continue to play this game.