Based on personal experience, if you like varied scenery and like to roadtrip USA style I'd nudge your compass a bit and go Chicago to Las Vegas, north route down and route 66 back. Driving Chicago to Miami is very similiar to driving London to Glasgow and lets face it Vegas is the ultimate "let loose destination". I do this trip every year from Toronto Canada in a muscle car and the scenery in the desert still blows me away every time.