Radio frequency signal transmitter

Here's some popular IR codec code for AVR/Arduino: http://www.righto.com/2009/08/multi-protocol-infrared-remote-library.html https://github.com/shirriff/Arduino-IRremote

You will need to choose a remote-control, and then program the AVR to do whatever it is you want the car lights to do when you push various remote buttons.

• Component 1 is a 2-pole, 2-way or double-pole, double-throw (DPDT) switch.
• You have drawn it correctly. When the switch is thrown the motor will reverse.

The second circuit is as clear as mud. I think you just want to switch a load with the remote receiver.

^{simulate this circuit – Schematic created using CircuitLab}

Figure 1. A typical method of solving this.

• Use a voltage regulator to step down the voltage to your receiver.
• When the receiver output turns high it switches on the transistor which switches on the load from your unregulated supply. Any small signal NPN transistor will do.

... but my goal here is that i have 1 energy source,

That's the 9 V battery.

... and the remote receiver has to receive a lower voltage (I forgot to draw the resistor) than the component

That's the 7805 voltage regulator. A resistor isn't suitable as the voltage at the end of it varies with current. The regulator maintains a constant voltage output; +5 V for the 7805. That may or may not be what you want for your receiver. C1 and C2 prevent the regulator from oscillating and are recommended in the datasheet.

The receiver has to have an output to be any use.

... receiver has to receive a lower voltage ... than the component on the other half of the circut (LED).

If you want to use a low-voltage receiver to switch a higher voltage load the standard approach is to use a transistor as shown.