There are no parts available from anyone but Tesla. So when the $2,500 plastic lens assembly for your brakes is back ordered 3 months, the insurance company is stuck with your rental coverage.
My immediate guess is because other car companies outsource the production of most of the parts, and the companies who make those parts are happy to make more to sell on the aftermarket.
Tesla manufactures parts itself, and is still getting their main production lines working right.
Tesla does. But builds most of their parts in house. And even outsourced parts may wind up inside of the part you need to replace, and therefore you're still bottlenecked on Tesla.
Perhaps you and I use different terminology? Parent comment refers to "full coverage", which I believe includes the costs of repairs no matter whose fault it is.
Full coverage auto insurance still only covers repairs from accidents. It doesn't cover the cost of, say, brake pads needing to be replaced or a window motor going bad.
For covering normal wear and tear maintenance, that would be an auto warranty – or extended warranty, service contract, protection plan, etc.
At least, those are the standard terms in the United States.
Anecdote: last year I was repairing a bumper on my older Ford sedan, this was in Minneapolis mid winter (so tis the season for mild-severe body damage) and one of the body shops I got a quote from was also the only authorized Tesla dealership in several hundred miles. They had an entire lot just for body damaged Tesla's waiting on parts. The owner commented to me that they were getting Tesla's hauled from southern Iowa for repair. Nothing like a 500 mile flatbed ride to really spice up the total cost of repair.
It seems like there's some confusion here with regard to auto insurance, warranties, and regular maintenance.
As far as I'm aware warranties only cover faulty / defective parts (and labour to replace), insurance is intended as accident cover, everything else is regular maintenance.
It does however factor in the likelihood of a crash, and the cost of repairing the vehicle after a crash. So if the 3 is more expensive to repair than other similar vehicles, the insurance would cost more.
