I've found out lately that the biggest reason that most automotive enthusiasts shy away from the road course is because they're afraid their car isn't ready. That's the wrong way to look at it. It doesn't take a fully prepped race car for you to be a better driver, or a better defensive driver. Being on a road course teaches you more about car control than you'll be able to experience on the street, I guarantee you that. I highly recommend that every enthusiast spends at least a day learning the car's abilities in a safe and controlled environment, it also truly helps when you have an instructor coaching you on car control.
A common question I'm always asked is how do I prep my car for the road course? My response will always be the same. The more you modify a car the harder it will be to drive; you're raising the car's limits. It's the reason every magazine loves the Toyobaru twins, because the limits of the car are so low that an average Joe can reach the limits at a speed that won't kill you. Now look at a car such as the Corvette or Viper, both of those cars have their limits set so high that most magazine test drivers find it difficult to push and hold the car at its limits. An error in a car such as that could land you in the ambulance. When you look at what the car is designed for and how many years of engineering went into making a masterpiece such as that, the car deserves your respect for it to be driven at the limit.
In short, you don't modify your car for your first few times attempting to reach the limits of your car. Obviously upgrading the brake fluid, brake pads, and decent summer tires will always be a must, it's basic safety. The biggest thing that helped me become a faster driver is investing in a racing seat, having the ability to always be in the same position no matter how many g-forces are being pushed on me helped greatly. Remember that smooth is fast (http://pramoda-ravi.kinja.com/what-it-really...), and being a fast driver doesn't mean you must have a fast car.
(Picture was taken at Gingerman Raceway in South Haven Michigan at a 3 Balls Racing event)