This type of 433mhz transmitter is not good for a project like this. Because it is a bit noisy. Use Xbee or Zigbee module. You can get an idea from here " https://blog.arduino.cc/2012/12/23/xbee-controlled-4wd-wireless-robot/ ".

BO motors have low torque. Use single shaft dc motors instead. Use side shaft for more torque.

Use lipo 3s instead of 9v battries for the robot. ( 9v battery can be used for powering the transmitter section with a voltage regulator )