I see your flipside Poppin, but I think car enthusiasm has lot less payoff then bass enthusiasm. I too sunk a bit of money into vehicles when I was young and have nothing to show for it. I was into the mini truckin thing and now,...I don't even own a car.
It's not a regret thing, but the money could have been spent or saved a little more wisely. I could at least get a little more than half what I paid for my bass I bought 10 years ago for $1500. Unless mommy and daddy buys you that stuff, most kids his age don't enjoy such things. I wish I had an Acura at his age,...I had a beat down gas guzzling 10 year old S-10 Blazer, before that was a nearly 20 year old Datsun PUP, that I wanted to "tune". Anything I tried to do to it (lowering, exhuast) just destroyed it further.
I still stand by my statement that the car tuner culture is a farce. It looks very glamorous on the outside, but in reality those cars are a lot of smoke and mirrors. It takes a lot of money to build cars to reach magazine centerfold potential (as it does to create tattoos that reach magazine potential) and the reality of the situation is that most attempts (at least for cars) fail,...miserably.
You need no more evidence than to take a drive around town and count the number of poorly executed "tuner" cars that you see. At least in my town they far out number the show quality and decent daily driver ones. I shake my head

at least a dozen times a day and see maybe one car and go,...nice job maybe once a week.
The guys with the bumpin systems,...hope you keep a doberman in your car at night,...people in this town are so hard up for their drugs they are robbing pharmacies of their oxycontin. Don't think for a second they won't think twice about breaking into your car and stealing your subs,...again YMMV.
For Optimus' sake I think we are trying to get him to see the adult perspective, perhaps to reinforce what his parents have already, hopefully told him. We were all teens once and we all thought we new everything, but alas we were wrong weren't we. I think the biggest revelation came for me when I acknowledged that I knew nothing.
EDIT: I think what we are trying to say is focus on education and growing up, then worry about the AMG Mercedes, and 65' Jazz Bass and Tattoos when you can actually afford them.