The G is my first car so I don't know exactly how it works. I'm assuming that when you trade your car, they will pay you for what the car is worth and whatever difference is left it gets added to the new car you buy. Is this how it works?

 

You got it.

 

Yessss...but understand their idea of "worth" may not agree with yours, so go in armed with KBB and whatever other ammo you can find that supports a higher value.

Also, you will typically get more money by selling to a private party, then buying the new car (yes, including the tax break)...