Take all that Turtle Wax crap back. If you've never wet sanded, now isn't the time to learn. If i were you, claybar the entire car, get some Mirror Glaze #2, #7, and your choice of topcoat (#26 will work, for instance) and take your time, and go at it. Also, that scratch looks like it's below the paint surface, so you ain't fixin' that with polishes.
Edit: If you do nothing more than hit it with a cleaner wax, Claybar it first. You'll never get it as slick without the 'bar. It's a 15 minute process.
