If the boy is into video games, he's probably very goal oriented. I lift weights and funny thing...the guys that come in scrawny and leave built are the ones that are breaking a video game habit. They're a very goal-oriented lot.
From what you describe about sitting at Carlisle, baking, well....What was the goal for him?
Parts cars, nothing able to be finished reasonably...What is the goal for him?
No money, no time, but plenty of project and parts cars? Well, I'm NOT trying to be mean here, but it sounds like the typical "Imma fix 'er up someday" syndrome. Too many dreams, and not enough dough. (remember, time and money are interchangeable, too)
My suggestion? Work on a firm goal for yourself, and if the boy is into video games, if you approach him with a firm, realistic, achievable goal that he can be a part of, he'll come back to you. No ride in a car does that; it'll just remind him of what's out of reach with you right now.
Ideally, you'd pare down the "stuff" in your life (Read: Sell all that project crap. You're probably never going to get to it anyway), and you might just end up with enough money, time, and space to get something done on the one car that is really important to you, and you might have someone ready to share that/those goals with you.
Remember, you can't change other people. You can change you.
Make a plan to get rid of the extra stuff and get something done on one car, and then ask him what he thinks...