I just had a total RDU failure, with my late 2014 P85D with about 65,000 miles, stranded out in the boonies. PRND all red, with a service required message. I could shift it into D, but as soon as I stepped on the accelerator, everything went red and locked up. Luckily a forest service ranger station let me use their landline, which I assume went via a satellite link, to call Tesla service. They were there in 3 hours and towed me approx. 100 miles to the service center, where it is currently getting a new RDU. Roadside assistance is wonderful, great to have if needed.