So mine died a month ago. I had 2 weeks left in the 4 year warranty, but I was at 60k miles, so they said it was not covered.
Advisor quoted me the roughly $1500 for a remanufactured MCU1, or $2500 for MCU2 (which loses the radio). I told him (nicely) that this was unacceptable since it's a manufacturing defect, and that they are even being investigated for it. After this, he said they could also try replacing the MCU1 Tegra daughterboard. This would be around $350 ($120 for the daughterboard, the rest labor) - but he wasn't sure how long it would be to get. Since I don't need the car these days I told him I could wait.1.5-2 weeks later the daughterboard came in ... but the repair didn't work. Another advisor called me back and said it didn't work, so back to the original $1500-$2500 options. I called the first advisor back, and he told me he had already ordered a remanufactured MCU1 (at their expense), and that they would swap the "frame" of that into my vehicle. Took 1.5-2 weeks for the new part to arrive. So in the end (after almost a month), I have the car back with a 64 GB remanufactured MCU1 at a total cost of $350. Find a service advisor who is willing to go to bat for you!