funny smell inside of car

I drive my 97' GTP to school every morning. My dad usually backs my car out of the garage, just because he wants to check it over to see if i'm takin care of it. This morning, there was a smell like something was burning inside the car, but you could not smell anything outside of the car. All the gages were normal, but I have been noticing that the windshield has been fogging up and the defroster does not help. My dad thinks that maybe there is an antifreeze leak and it is spraying over the windshield and that is why it is fogging up. Can anyone help me?

Is the fogging on the inside of the windshield or on the outside? If it's on the inside, maybe the heater core? Is the burning smell an electrical one or something else? Either way, keep a careful eye on it.

I'd put my money on a new heater core.