Ideas on trading a model S for model Y?

Hi All,

Back in 3/2020, I bought a 2016 model S75 from tesla when they had their promotion that gave 4 years/50k miles of warranty on them.

I recently upgraded to a model X, and wanted to trade in my model S for Y for my brother. It's in great shape, only has 46k miles and still has warranty until 3/2024... but we are getting low-balled to death by these dealers. I know private party would get me more, but I was hoping to find a way to do swift transaction where I would just trade the car, pay a bit more, and get the Y from a delaer that has a used model Y.

Any idea on what Tesla is offering on trade-ins these days? Any other ideas on how to make this a bit easier? Are there good "car trading" sites where maybe I can find someone that is tired of their Y and wants an S?

Thanks!