OK, I was originally thinking that making up an adapter plug for a Nissan alternator could be far worse - especially if a Toyota part wasn't available... But it's all totally sloppy bush-league work. Yikes!
There is also this one, the Diode Dynamics SmartTap CF18. It's expensive, but kind of cool.
https://www.diodedynamics.com/smarttap-cf18-led-flasher-module.html