Do they still make specific aftermarket brand wiring harnesses these days? When I started messing around with car audio, I was able to buy a (certain year) honda to clarion wiring harness, that directly connected the factory harness to the back of my head unit. However, in my past few installs after that, I've only been able to find generic adaptors, like Honda -> open and open -> alpine, and had to crimp the wires myself. Do they still sell, say, a late-model Nissan-to-Alpine adaptor these days?

Searching crutchfield.com didn't help. Their accessories page is quite cumbersome to navigate :/

 

Try CALLING Crutchfield. Their service representatives will help you for whatever you are looking for. Believe me, they seem to have everything for car audio for almost any car make.