The Strati 3D printed car is a nifty thing, but the 1/10 scale model files they posted have some printability issues. The wheels are especially bad, so I have taken them and reworked them to be more amenable to printing and customization.
First I've turned the wheel to be flat on the bed. Radially symmetrical objects should always be printed flat, this way you don't get a flat spot and uneven distortions on the wheel. The flat side of the wheel is now the side that faces the inside of the car, which can't really be seen once the car is assembled.

I've split the tire and rim into separate pieces, so you can print them in differently colored plastic now. If you have a printer that can print elastomeric plastics, you can make an actual rubber wheel. I have also split the rim into two different pieces to be assembled around the wheel, since there would be no way to get the wheel into place otherwise.

I also redrew all the geometry and simplified a lot of details that don't even show up in the scale this is being printed at, and made the ribs thicker to make it possible to split them in half, and also to give a bit more strength to the wheel.

Print out all three pieces. You should not need support. Push the inner rim into the tire piece, it should go in snugly and hold together just from friction. You will then need to glue the outer rim onto the outer side of the wheel, since there's not enough material on that side to hold it in place just through friction.