With some Power Functions elements and a few extra pieces, it's pretty easy to turn the Rally Car into an RC car.
Here's a quick demo video of my design in action.
And here are the instructions I made for it.
Required extra pieces
First you are going to need some extra pieces:
1x - Servo Motor
1x - IR Receiver
1x - Battery Box
1x - L-...
Rebrickable has an option to compare set's main models and some of the B-models as well. However there is no inventory for second model for 8285 set available on Rebrickable. The best I could find is a LDraw file available on Eurobricks.
I've imported this file as a custom list on Rebrickable that could be used to compare with sets and MOCs. Imported file ...