This is a Pixar movie set in Mexico. When Mexico or Latin culture in general gets depicted in Hollywood, it's usually a sad caricature of the real thing. Two recent high-profile shows come to mind:
Breaking Bad, one of the best TV shows ever, does a terrible job of this. The main bad guy is supposed to be from Chile (???) and his Spanish was beyond terrible. Everything else was about the same.
Narcos, a TV show filmed in Colombia about a Colombian drug lord, chose a Brazilian to play Pablo Escobar. You can tell he tried, but his Spanish is off in an Uncanny Valley kind of way. There are other questionable casting choices.
In a refreshing contrast, Pixar seems to have done it's homework. The clips look and feel like Mexico. And whenever a character says something in Spanish, it sounds like a native Mexican Spanish speaker. Looks great and at the same time very respectful to the culture. How refreshing!
In addition to being a great movie, Who Framed Roger Rabbit is an impressive technical achievement. It still looks great. This video goes into the work and attention to detail the director and animators went through.
Should be noted, Robert Zemeckis also directed Back to the Future, one of the most entertaining movies ever made.