I was reading up about some iPad apps and stumble upon this app, its a great app in Appstore for USD$4.99 and the controller for iPhone is free. What it does is that it connects your iPad and iPhone through WiFi and you control your car using your iPhone. Works seamlessly in Wifi and AMAZINGLY on Bluetooth, all you got to do is just turn on both Bluetooth and let it find each other, no pairing, nothing. AMAZING! Didn't know Bluetooth could do that quickly without even pairing.
The great thing is if you have 4x iPhones, you can play up to 4 simultaneous user racing back to back. That's not all, if you happened to have 2x iPad, you can combine the tracks together on the iPad and link them whilst racing together with your friends.
Here's a video of me playing the thing. Thanks to @ruhanirabin for the video (Coz i need to use my iPhone for the remote LOL).