My Best Buy card has 0% for 18-months. Indefinitely. I can "stack" purchases, and pay them off 18-months at a time, at 0% interest. As such, Best Buy is where I prefer to make my large purchases. In the last three years I have purchased my Bosch dishwasher, 55" HDTV, Canon EF 70-200mm f/4L USM lens, and my 27" computer monitor all through Best Buy, and all at 18-months 0% interest.
Naturally, I assumed I would purchase my car stereo and installation there as well. Only, I was wrong. When I was presented with a $275 bill for installation alone - four speakers and a head unit - without having yet picked any components, I was sure a better deal could be found elsewhere. Like the guy who charges $50/hr and estimated two hours for the same components. Unless I didn't purchase the components he has for sale, then his hourly rate goes up. I did check on his components - the entire installation would have set me back $562 plus tax.
That's when I decided to do it myself.
Because I'm dumb.
Or stubborn.
Or both.
At any rate, I ended up with an
outstanding 100x4 (40x4 RMS) Sony head unit and two pair of Kicker 6x8 speakers. That was the easy part. I picked up a Ford-Ranger-to-Aftermarket adapter, because I thought, well...you'd plug one end into the "Ford Ranger" harness, and the other end into the "Aftermarket" harness, but that would have been far too easy (and upon retrospect made more sense since each aftermarket stereo presumably uses its own unique wiring harness). Last time I did this I was my son's age and wiring anything newer than my Dodge AM Radio into my 68 Coronet 440 with miles of electrical tape. Looking at the rat's nest of wires I had to splice together between the two adapters before they would work as I described, I settled on screw on wire connectors and drove down to the local Auto Zone. When he was done laughing at my request, he introduced me to heatshrink crimp connectors because they don't carry screw on wire connectors anymore. On the upswing I can now get cracking on that crème brûlée I never wanted to make with my new Chinese manufactured butane torch.
Anyway, the heatshrink crimp connectors looked super easy. They weren't. And I somehow ended up with the exact number of connectors I needed, which meant I had to find a way to fix the ones which crimped improperly. No, seriously, how difficult can it be to crimp a goddamn wire? My success rate was something like 80%. And I had less and less room to not burn the shit out of my fingers or the wires behind the connector with that damn blow torch the more connectors I put together. But eventually, I got that done as well.
Now, when I graduated high school I worked as a porter for a large Buick dealership, and spent most of my downtime with the guy who worked trim, so I was at least familar with a lot of how those large pieces of plastic get attached to the metal skin of the interior - which is to say, I was not at all looking forward to tearing and ripping the inside of my truck apart. But I did anyway, to remove the old, dusty, paper speakers from their moorings. A couple of Ford speaker adapters and closed-cell ("Boom Mats" I think these were called) and
the speakers were the simplest part of the entire installation.
The greatest dismay was the universal mounting faceplate, which had "super easy" and "1-2-3" mounting instructions. Unless you had the Ford Ranger, in which case all I had to do was remove half a dozen tabs with some sort of cutting tool. Exactly the type of cutting tool I didn't have. So now I have a Dremel. But that's OK because I've lots of uses for a Dremel. Anyway, it all eventually went in, and while I was inside the truck doors I took the opportunity to tighten everything up which was otherwise loose or rattling, and put everything back together. The truck looks good, and now sounds good too.
But I hope to never do that again.
And I figure the whole thing cost me $450 anyway.
But I got a much nicer head unit with the money I saved by not paying someone else.

And it took me a week.