Yes, rats have been trained to drive.
Not actual cars, but small vehicles in a lab. They can control left, right, and forward. The rats learned to drive to get food. And scientists found that learning to drive seemed to reduce stress.
The ability of rats to drive these cars demonstrates the “neuroplasticity” of their brains, says Lambert. This refers to their ability to respond flexibly to novel challenges. “I do believe that rats are smarter than most people perceive them to be, and that most animals are smarter in unique ways than we think,” she says.
And there are neat videos of rats driving their “cars”.
Here’s another article that includes information on the two groups of rats involved, including that they seemed to enjoy just driving their cars even if there were no treats involved, but only if they lived with many other rats in an enriching environment.