We went and dropped off the Prius. If the rental agreement is correct, we drove 885 miles (it didn't occur to me to figure out how to reset the trip computer when I left), which means we averaged 45.2mpg. Not bad :o)
After Vic left for work, I started work on the solar panel for the roof of the van. I took the luggage rack off the front, and made up mounts for the solar panel. I'm running the wires down one of the water drain holes, so they have to be put in place before I do anything else, as the connector ends are too big to feed through the hole. I've put garden hose filters over the other 4 holes, so that hopefully the next time I have the rack off, it won't be full of dead insects and foliage. I also took out half the bloody interior so I could get the headliner out - the wires will be going under this. While it's out, I've added a few strips of the tar paper, to help quieten things down by changing the resonance.
In the evening, I had an email conversation with the seat (for the van) seller, and they're sending me a replacement.