All I can possibly remember is that the MC is in a male body (so an episodic novel) and is technically a slave/servant. So the original body was a young master but was schemed by the step mother and brother to drink this drug that made him appear mad (like a bad disease in the plot) so he was sent to a servant institution where he was assigned to some big wig guy (the ML). Servants are basically robots and are the lowest grade in humanity existence because they used to be regular humans but due to the "mad" disease become lifeless robots with no conscience (they'll do anything ordered to). And I hope this can be a helpful clue, but the MC shows some rad mad skills in car driving. (That was shown at least twice in the novel and was basically the climax point) The MC also subtly shows some conscience in order to push the plot forward but not a lot to ruin the plot. I hope my description is pretty accurate, and thank you even if you don't know it. Thank you even more if I can read it. Good day.