Hello,friend! I will share some idea about how to make a Arduino 
Multi-Function Bluetooth Smart Car.How do you like it?

The Arduino Bluetooth Smart Car from www.icstation.com has the function 
of Complete tracking, obstacle avoidance, infrared remote control and 
Bluetooth remote control. It is a MCU study and application development 
system base on Atmege328.The greatest feature is that you can control it 
with Mobile phone bluetooth of Android system. That’s may have a lot of 
fun.To make it, you need a number of kits which contain a number of 
interesting programs, and expand external circuit module to implement 
functions.

You can know more details from 
http://www.instructables.com/id/Installation-of-Bluetooth-Multi-Function-Smart-Car/where 
I post.