Good luck. They won't fix it. I thought Canadian buyers got a mudflap kit included, or is that only certain provinces?I feel that mudflaps and PPF at least on the rocker panels and doors are essential. I wish I would have researched this ahead of time and applied these to my new M3 (Sept 2021). After the salt and sand damage from just one winter (I live in Southern Ontario, which has shorter and less vicious winters) I am very upset. I can't imagine how terrible the car will look after just a couple of more winters! The paint on this car is extremely crappy. How can Tesla sell cars with paint that isn't durable? Now I have to spend time and energy begging for them to repair it, taking it out of town to the Service Centre that has a very long wait list to get in, and I'm preparing myself for disappointment (poor service or response delays, or if they don't honour my problem). Got a new car? Assume the worst will happen to the paint in winter and take measures before it happens, that's my advice.
The problem is the rockers are aerodynamically undercut. The paint may or may not be any softer than other mfrs, but the problem is mostly one of design. Most mfrs have a vertical side, to prevent dirt and debris from being thrown up by the tires hitting the paint on the lower part of the car. Tesla doesn't do that, but makes the underside as aero as possible. That exposes the rockers to an insane pelting. No mfrs' paint would survive that. You need mudflaps and/or PPF to protect the rockers. Flaps are a cheap fix, some people have bought generics, that they cut to fit for under $40. PPF can be bought to protect the rockers, and the dogleg and the lower part of the doors for $200.