I have a 2016 QX60 with the factory installed DVD system. One of the screens is cracked and inoperable. Service says this cannot be repaired and must be replaced - to the tune of $4,000. Surely there is another option. Ideas?
That's part and parcel with service. If you buy a car without the DVD units, and want to have it added after the fact, it's quite expensive AND they're not even the same ones you get installed when the car comes with it. Considering a non Theater packaged car with Navigation still plays DVDs just fine in the dash, it's likely it still has the AV out ports. All they would need in theory is the headrests and run the power and AV cables to the dash. I know because I installed my own TVs on my Maxima (along with Xbox and other things). But Infiniti service looks at one like we're crazy for even suggesting it.
Anyways, in your particular case, best bet would be to find a replacement screen (eBay, local junk yards, etc) and replace the old unit with the new one. It's something you would need to be comfortable tinkering with car electronics to do. But it's doable.