Yes that's right I'm making a free roam driving level, and I only have one major thing left to actually do before I can release (an early version) to everyone!
I havn't even attempted the steering and that is what I am here to ask, what is the best way to do this? I would like it so when the user holds down left stick right/left it will steer the car.
I had exactly the same problem. Try placing a fresh copy of the example car in your map, 3 directional forces (or however much you are using, i used 3; forward,backward and steering).
Now select (with the multiselect tool LB) the directional forces, and only the body of the car. Press up and glue them together. Should work now, it messed up my wheels and suspension too, but after i've done it like this, it works, there's an example on track central.
I'm pretty sure that the problem here was that you tried to glue the objects which were connected with joints together. Objects cannot be both glued and jointed together. Glue overrides the joint connection. So, you should first glue the things you want to glue together and then make your joints with some object outside the glue group and with the glue group. Then you can adjust the pivot points to be in the correct sub-glue object.
I started again and got the car (with the physic wheels) accelerating, braking/reversing, sounding the horn (with left stick in), and was just about to finish turning on the lights (with Y).
Re: Check out my upcoming free roam (Need help, too!)
i used a directional force at the front, not too much force, but just enough to make it able to steer when its moving. If it's standing still the force shouldn't be able to move the car. It seems the force is only pushing the front of the car, so the rotation is actually pretty realistic, you just have to fine tune the force settings.