taco tunes sells 2 different harnesses stopping at '15.
05-15:
https://tacotunes.com/shop/toyota-ta...rness-adapter/
16+:
https://tacotunes.com/shop/toyota-ta...ness-adapters/
they look really close, but the plastic appears different. typically, toyota generally keeps to the same harnesses for all vehicles for simplicity, though there's no law about it. honestly, the '16+ harness looks closer to what i recall of my '14 tweeters.
the main advantage to the 16+ tacotune harness specifically is that they provide extra wire on both the 'input' and 'output' sides of the connector that other brands don't, like this version, which has only very short wires that then jumper across the 'input' and 'output' parts of the connector.
https://smile.amazon.com/RED-WOLF-20...75&sr=8-4&th=1
could try to contact oem+, though i haven't heard too many positive indications from others-- oem+ understandably seems to only want to support their own products, and doesn't seem to want to get involved in others projects.