GBG Nebraska has come up with a simple steering modification.
Feel free to use/improve it. 
Steering While Driving ½” PVC Instructions
Items needed:
~12” of ½” PVC (if you can get the type with the thinner walls as it will be lighter)
2 -½” PVC caps for the ends of the pipe (if you don’t have these the kids like to stick their fingers in the end of the pipe)
2 -½ or 3/4” plastic PVC Conduit Clamp it is also called a pipe bracket. (Try the bracket with the pipe at the store against a flat surface to make sure that it fits well. There can be a little space but not too much.)
4 -3/8” screws
Electrical tape (white is the best if you can find it)
4x4” ½-1” foam (optional)
Big Red Switch with plastic cover over the color
It is best to attach the bar/pipe to the switch before attaching the switch to the steering wheel. If it is attached to the switch first, when you put it on the steering wheel you can make sure that it is horizontal. If the switch is already on the steering wheel, the switch can be removed and put back on after the bar is attached or it can be put on while it is still attached. See instructions below.
To install:
Place the switch on a flat surface so that the cord is towards you.
Place the bar on the switch in the middle of the circle.
With a pencil, mark the top and bottom of the bar for reference.
Place a bracket over the bar about 1-1 ½” in from the left edge. Mark the top hole with a pencil or marker. Take the color lid and the clear lid off of the switch really trying to keep the lids together. Put the lids over a piece of wood that can be damaged. Drill a small pilot hole through the lids. Screw the top of the bracket onto the lid. The end of the screw will barely poke out of the bottom of the lid. Take the electrical tape and put a few wraps on the bar where the brackets will go. (The electrical tape helps keep the bar in place and also makes up for the curve on the top of the switch.) Put the bar in the bracket. Make sure it is lined up with the horizontal lines. Put the right bracket on 1-1 ½” from the right edge. Mark the top hole with a pencil or marker. Drill a small pilot hole through the lids. Screw the top of the bracket onto the lid. A 2nd person is helpful for the next step. Have one person hold the bracket down and in over the bar and the 2nd person, if you trust them, drills the pilot hole or marks where the pilot hole will go. Put the bottom screws in both sides. Put the caps on the end of the bar. Put the lid back on the switch securely. There are 3 ways that the lid can start and the bar can be in 3 different positions. Find the way to start that will have the bar going horizontal when the wheels are straight. Have the lid on tight.
Attach the switch to the steering wheel using 3 zip ties. Make sure that the wheels are straight forward and the bar is horizontal.
If the switch is having a hard time turning off because of the weight of the bar, put some small 1x2 pieces of ½ - 1” foam under the black bars that look like pieces of pie under the lid.
You should be ready to steer while driving. J
