One trend in the evolution of the car is the simplification of controls, even at the expense of making the internal mechanisms more complex. Cars that were previously started via a crank mechanism were followed by cars that could be started from the inside. Currently, cars are made to start at the push of a button. However, the starting mechanism itself, from the transition from crank to button, has itself become more mechanically complex. This has an effect on car repair, necessitating ever more specialized technical knowledge of car repair workers.