This is a compilation of three episodes ("World's Finest" Part 1,2 & 3) from "Superman: The Animated Series."
The movie was based on the Batman and Superman animated series, part of the "DC Animated Universe" (DCAU).
A probably unintentional one, but it's mentioned that previous owners of the Jade Dragon all met early demises due to the fact it was made of kryptonite and the radiation coming from it. Years later in Justice League we find out Luthor held a small piece of kryptonite for years to keep Superman at bay and caught a terminal illness from it. (Then again, the latter was a plotline that had already played out in the comics...)
The phrase "rich Corinthian leather" which Joker tells Lex Luthor the car seat is comprised of while riding in his vehicle is a joking nod to the phrase used by Ricardo Montalban which he would use to compliment the car interior in advertisements for Chrysler. In reality, "Corinthian leather" does not exist and was instead an invented term for marketing.
Though hinted at previously, this cross-over episode cements the idea that Superman the animated series and Batman the animated series take place in a shared universe. This establishes the idea of a shared cinematic universe, or what has come to be known as the DC Animated Universe (DCAU for short). Laying a blueprint for what Marvel would later replicate with its MCU (Marvel Cinematic Universe) starting with Iron Man in 2008.