Why would a rattling noise occur from the front brake on the drivers side?

It's possible it may not even be the brake. Check the link between the front sway bar and body of the car. They are made with plastic cups that the ball section sits in and can easily brake causing a clunking or rattle sound. You may need to remove the link from the car to check it. Even if this is not the problem you may want to consider upgrading them with an after market kit. I would also add a rear sway bar. The car will handle much better (use aftermarket, the dealer will rip you off and it's an easy job). Good luck. I hope this helps.