Some people like to use technology, look genius in front of other people or there own kids, here is a way to do that!
I can give you full details for a project you can do yourself that will modify your own RC car to work by any android mobile phone via Bluetooth!
Just by parts I give you links for, connect them together as you will see, download program to your android and you are done!
You will get RC that works on Bluetooth, smooth control, can even control speed of car (even if not supported by original car), and can control lights and horn (should be supported by car, if not then you have to put LED lights by yourself)
You don't need much experience to do this, just follow instructions!
I will always help if you face any troubles.