Traditionally, this was done with a device called a distributor. Some time in the early 70s, engineers realized that point-breaker ignitions were a major pain, so they came up with the first electronic ignition systems, which used a sensor in the distributor which decided when the rotor was nearing a contact, then turned on the juice. Suddenly, folks were getting 30,000 miles out of a set of spark plugs, instead of 10,000. In the late 80s, the engineers went one better with the distributorless ignition system. Today, most cars have DIS, and those that don't have an electronic ignition.
Brakes slow a car down by converting motion energy to heat energy.
Back in 1969, you could still get cars with drum brakes on all four wheels. Another problem with drum brakes is that when they get wet, water tends to stay inside the drum, reducing braking effectiveness. In the late 60s and early 70s, disc brakes began to appear. Imagine spinning a paper plate, then squeezing the edges to make it stop, and you'll understand how disc brakes work. And when the rotor gets wet, centrifugal force simply flings the water off.