I just can't fathom a huge market in stolen car parts. I do a lot of my own work and always just go to NAPA or maybe rockauto.com and buy any new parts I need.
Maybe there is a sizable black market of major parts (engines, transmissions, body panels) etc. to unscrupulous repair shops?
I've always owned 10-20year old cars, and frequently replacement parts aren't available; I have to find them on ebay or craigslist and I've no way to know weather these were scavenged legally or stolen.
I've also used Craigslist because new parts can be 5 times more expensive than used parts. You may buy all your items new, but most of the working class people on my block, who are constantly upgrading their cars, probably can't afford it. So, I have no problem imagining a large black market.
I suspect most stolen parts would either be sold through Craigslist of junkyards. The old timers still rely heavily on junkyards for parts. I've been to quite a few, they tend to be shady.
Maybe there is a sizable black market of major parts (engines, transmissions, body panels) etc. to unscrupulous repair shops?