Instead, he's driving the piss out of his mom's Taurus

Another vehicle he can't afford to fix if he blows it up.
How far back do we go on this train wreck? The Honda? The Expedition? The Blazer? The Volvo? Systematic destruction through abuse and neglect while burning money on useless wizards to address wholly imagined "problems" while tires are run to the cords. The vehicles, rolling liabilities, eagerly courting disaster, being piloted at speeds they should never be going, mere inches from people totally oblivious to the rolling hazard blasting by them.
As you note, some nod given to responsibility with money and avoiding blindly casting it into the void would have allowed for purchase of something in decent mechanical condition with good reliability. Instead, there's no money, and efforts are being made to accrue enough to try and source the 4th engine for a car that's clearly too far gone to be worth the time, effort, or expense.
I remember us having a conversation about what would be a smart purchase for somebody with limited means that would provide good reliability and minimal expense. I also remember that advice being soundly ignored, as it is now. It was frustrating then, and even moreso after, as the saga grew legs, chapters even. That's why I no longer engage with him. Why bother putting in the effort to provide sage advice if it always falls on deaf ears? Wasted effort, wasted time, wasted investment.