I'm not familiar with the car, but sounds like your steering horn is not in the center the servos range. Meaning that the horn is mounted closer to left handed range of motion, thus allowing you to steer more to the right than the left.
here's what you do: 1) turn the transmitter on, 2) turn the car on, 3) on the transmitter, make sure the steering trim is set to 0, 3) turn the car off, 4) turn the transmitter off, 5) adjust the steering horn to center position. That should do it.
It's a little easier to do than explain. If anyone can explain it a little clearer, please do.