Is it possible to do car physics with commercial a6? with wheels? because you can only have 1 object using the physics, wouldnt it need 5 objects to use the physics engine? 4 wheels and the body of the car

Its possible, I just wrote an article on it. Check the User Contribution section for Basic Physics Scripting.

yes, but that does not have wheels, what i need to know is if i can have a car with rotating wheels etc

you cant have more than one physics object in com version, so using a script like ventilators, that uses wheels (requiring four physics objects, at least) wont work.

thanks

Is physics in Commercial version more or less a demo version as it is just one object?

Just a thought I had about the 1 physics object in the Commercial version: is it possible to alter the entity which has physics properties on the fly?
What I'm wondering is if you can have it so that you could 'fake' physics for several entities by simply checking which one 'needed' physics at a particular time. Then your code would apply the physics properties to the required entity. Then, when a specific physics task was not required you could swap it back to a more rudimentary set of physics instructions.
Probably more hassle than it would be worth, but it's a thought

you can

Yes, I believe you can have many physics objects in the level, but only one enabled at a time (but not positive on this). You can easily fake many physics properties as I did with my first pinball tutorial.

The com version isnt really a demo version, as there is quite a bit you can do even with one object (tennis, golf, bowling, vehcile, moveable boxes(one at a time), etc).