https://help.doordash.com/dashers/s/article/Does-DoorDash-have-auto-insurance?language=en_US
If they were on an "active" delivery it sounds like you could take it up with DoorDash.
Carvana is building a car vending machine in its place.
https://www.nbc4i.com/news/columbus-business-first/carvana-vending-machine-planned-for-polaris-magic-mountain-fun-center-site/
How long will she be keeping the car? If the answer is another 100k miles then splurge for the more expensive unit
If the WP goes out will it take the timing belt with it? if yes, then go with OEM part from dealer