Automakers found the one way to make schizophrenia cool.
In the 1980's, cars began to gain efficiency and performance benefits by using computers to regulate variable engine parts like fuel injectors and spark plugs. Until recently, the computer made all of the decisions as to how the engine would perform, whether it set the engine up for speed or to be anorexic regarding its fuel consumption. Tuners use ECU modification systems to upload new engine maps into their cars and get more power out of the engine.
Factory engine maps usually prioritized fuel efficiency and preservation of engine components, but tuners were able to throw caution to the wind and get considerable increases in power by altering ignition timing, fuel air mixture, and more. As automakers wised up, they learned that they could do all of this for the consumers and tack it on as a selling points for a car. This enabled cars like the BMW M5 to be civilized and boring enough for accountants on the road. But at the push of a button, a wild beast emerged ready to tackle slaloms and racetracks. As complex as these systems sound, it turns out they aren't more than a collection of variable parts changing their settings in concert to drastically alter the personality of a car.
In fact, the most basic driving mode systems don't really do much at all. Modern entry-level cars have them and usually three modes are available; eco, sport, and normal. Normal modes retain driving characteristics that most people are familiar with in a car. Flip the knob over to eco and suddenly throttle response is scaled way back. This doesn't do much for the engine, but it makes it easier to save an MPG or two by allowing for slow acceleration and judicious use of the throttle. Sport mode does the exact opposite. It makes it so a feather touch on the pedal sends the tachometer searching for the redline. It also holds lower gears longer to enable quick acceleration and engine braking.
On most entry level cars, these settings hardly make a noticeable difference. High performance cars are the ones that reap the biggest benefits. Normal modes help the car comfortably putt around town and reserve the snarling acceleration and twitchy throttle response for sport mode. For example, cars like the Jaguar F-Type now have electric steering, exhaust flaps, traction control, and adjustable suspension. These variables allow for more changes in the driving or handling characteristics. When a driver is feeling frisky and wants to take their feelings out on the road, pushing sport mode will stiffen the suspension, shorten the steering ratio, give a weighty steering feel, open the exhaust flaps for noise, and tone down the electronic aids.
Combined, these completely change the character of a car. A simpleton who was once idling comfortably in traffic can now pull off high G maneuvers, tire squealing corner exits, and loud neck-jolting accelerations. The addition of these toys to mainstream cars is controversial. Sometimes automakers add systems like this to a half finished product to cover up a lack of balance in its cars. The ideal way to properly engineer cars with multiple driving modes is to design each mode well enough to enable them to extend a car's capabilities rather than splinter the personality. The less a driver has to play with the better because just like Ludacris said, all we really want is a lady in the streets but a freak in the bed.