i take a full size lab in mine. I have this seat cover:

https://www.amazon.com/dp/B07SX2NGYZ?ref=ppx_yo2ov_dt_b_product_details&th=1

I originally bought the OEM $150 Tesla one but it was a huge disappointment. It is no better than $30 ones on amazon. the one i bought on amazon allows human and dog passengers and it can stay on full time. way better than the tesla one.