I mean I haven't seen a serious article claiming full protection, usually something like 60% against catching delta, and a bit higher against serious complications. The vaccine helps you but it doesn't make you immune.
What it does is greatly reduce the speed of transmission - 60% reduction...
Unless those guys all blow up their teslas.
The other issue is that it's a matter of rate of growth; as long as Tesla is producing more and more cars, there might be more cars that need replacement batteries than there are cars that can donate old batteries.