Jon knew he couldn't outright undo the wish he had just made. He could only modify it. He hadn't specified that the car be on fire, merely "super hot." Well, there are a range of things considered "super hot." He made a new wish, careful to say it all in the same breath: "I wish my new car was not on fire, restored to look like brand new again, and hotter than the hottest summer day, ever, but well below the ignition point."
The stone glowed again, and as he looked up, the flames were extinguished almost instantly. The smoke cleared and revealed a shiny new sports car, free of any signs of fire damage. It looked impeccable, but the heat emanating from it was intense.
Jon couldn't believe it worked! He was ecstatic and sprinted towards his new ride. However, just as he was about to open the car door, he recoiled in pain. The door was incredibly hot to the touch, as if it had been left in the blistering sun for days. He could feel his fingers stinging, he had quite literally been burned by his own wish.
Undeterred and wincing in pain, Jon looked at the stone and said, "I wish my car will cool down naturally after being so hot." He hoped this wish would fix everything.
The stone glowed one more time. Jon cautiously approached his car, feeling the heat subsiding. He held his hand close, without touching the door. It was indeed cooling, but it was going to take a while.
Jon sighed. He had thought his first time driving a sports car would be a little more glorious than this. He looked at his red, slightly blistered hand and his still too-hot-to-touch car, and decided to leave it for the day. Maybe after school, it would be cool enough to use.
"I guess I'm walking today," he muttered to himself, pocketing the stone and starting down the street towards school. As he walked, he couldn't help but feel a little disappointed. He had a magic stone, and yet he was walking to school and nursing a burnt hand. It didn't seem quite fair.
As he got further away from his house, he turned back for one last look at his car. It was still there, shining and beautiful in his driveway, but untouchable. He sighed and continued his walk.
Jon had learned a valuable lesson about the Stone. It was powerful, yes, but it was also extremely literal. He didn't realize yet it had been switched, and he might never realize it, because he hadn't had enough experience with the original to know the difference. So he just knew now more than ever that he needed to be careful with his words, or else he would end up in another situation like the one with his car.
The school loomed ahead. Jon was just in time, he hadn't missed the first bell. He decided that he would make the most of the day and figure out how to use the stone effectively.