Yup, that was what I was saying, and glad you double checked @Riemann and that @ShadowFacts will be checking as well. Again, worst case, I don’t see how that it wouldn’t be legitimate damages (again in MOST) states for your lose of use - and again, if they won’t provide it ask if they will pay to reimburse you if you rent for your own usage as this has been an extended loss.
If the car is deemed unsafe w/out the bumper cover and other supplements (and the OP specified sensors included) then the dealer would be on the hook for any issues that occurred after they released the vehicle back to the OP, when they have no obligation to take those risks. For an extreme example, but one that isn’t exactly unheard of, the OP is driving the 95% intact car and is rear ended AGAIN, but this time has a cervical injury. Now, the OP can sue the daylights out of the dealer for the unsafe vehicle, including pain and suffering, and the limits are off due to comparative negligence.
Speaking from the dealer’s POV - why take the risk? I’m sure the repair contract has one or more clauses that specify that the dealer has to do good-faith repairs and return the vehicle in a safe condition if possible. Now, if the delay had been due to an error on the dealer’s part, then I’d argue that they would have an obligation to make other arrangements*, but for a (world wide) shortage on parts? Almost certainly not.
In fact, this is probably at least in part due to changing legislation designed to protect the customer from loss - the whole OEM part controversy changed a lot of how repairs were handled, and often not for the better. Especially on a 2020 model, there’s probably a requirement to have new parts in some areas.
*an example I had personal experience with, customer took car to shop after vandalism damages, which were repaired quickly, but the exclusive limited edition paint (which was specific to that model) required ordering paint from Japan. They pre-ordered it while doing the rest of repairs, and so it wasn’t much delayed, until someone in the shop was showing off the just painted car and not-realizing it wasn’t fully set/dried, put their hand on it.
So they needed another week to order paint from Japan and to repaint the vehicle, all on their own heads.