After hi-jacking my camera's miniusb-to-usb cord, because shockingly doing anything with the website requires a cord that your GPS doesn't come with. Some poking around later, it turns out that updating the thing once is like $80, and getting a lifetime update package is more than the cost of the GPS itself.
WHOA BACK, GARMIN. Odds that I, or anybody else rational, will do that is 0%. Geezoo, what a scam. So anyway, this is what the internet is for, and ten seconds on TPB turned up exactly the update that I needed. It took like 2 hours to do it manually because i was ul/dling a 1.2 GB file over a usb cord, but in the end i restarted the Nuvi and it looks just fine.
Um, except some of my saved addresses have some kanji in them now. And when I start it up it informs me that I'm loading 'the Queen's maps.' BUT HEY. The Queen's kanjified maps surely didn't cost me $80. You know, the thing is that I would have totally paid Garmin some sort of rational fee because I use the GPS all the time and I'm an adult with a job, but holy hell i was not handing over $80 annually, much less the cost of a brand-new unit. Good gracious.