I have a old RC car/truck with a good battery. It's starting is 2 dc motors on the back wheels (Skid steering?). Am I able to use a Raspberry Pi, USB web cam and a USB wifi card to make a RC car that can be controlled via web interface or program on a Windows Computer. (Android can work too, if all else fails). I am hoping to have as little lag as possible for stearing, I could make due with some lag on camera feed.
Yes, this is possible, I have done this although you have to piece together information from different sites to create this.
I would start by looking up how to control DC motors with the Pi and go on from there. For example, then searching how to stream video from the Pi. As for the program that controls the Pi remotely you can also do that but it would require using SSH. For that I would use some of the resources from here. Another site that may be of use is this instructables page.