I like how the turtle shines up when you use a good buffing glaze after the compound. It gets all of the swirls out of his shell. We all want our turtles to bling, you know.
Don't use rubbing compound on clear coat shells or recent Mustangs. A thick lacquer or enamel can stand rubbing compound then finer compounds with a good wax. But I have seen clear coats rubbed through by old timers when the OEM's made the switch. Your turtle will be happier kept clean and waxed with Meguires. It is much slipper and easy on the shell.