My car radio is having trouble reading CDs; I need a new one. Will pretty much any interchangeable radio fit in any car that has an interchangeable-style radio port? Or does it vary from car to car and I have to find one that's made specifically for Subaru Legacies?
While certain cars have specific dash units that include things like heater controls and such (Ford Taurus ovals come to mind), by far the standard has been set to 'Single DIN' (a majority of cars/CD players) and 'Dual DIN' (the size of two normal rectangle sizes stacked on each other, almost squarish compared to the rectangle of a Single DIN).
If it's at all avoidable, stay away from the 'fit-to-your-car' styles. When I buy a good deck, it follows me car to car. Also, since single DINs are manufactured in higher quantities, there are usually more choices and lower prices in the Single DIN selections. I see a few posts that hint to Subaru Legacies being able to be modified to accommodate a dual, which may be worth it if you really want GPS Navigation/a touchscreen.
After you select the deck, you can get a 'Subaru' harness that will plug into your wiring, or just cut the factory connector and splice the wires in yourself with the help of a wiring diagram. The connector method is nice because you can put your stock deck (or a cheap replacement) back in when/if you want to sell it but keep your deck.
You get specific Subaru radios, which are the simplest to fit, however I have always used aftermarket stereos in my Subarus, and the only work you need to do is tweak the wiring harness.
The wires you get are generally the same for most cars (if we exclude specific models which display engine, mileage and other data through the stereo front panel) but the plugs may be in a different position or order.
So an aftermarket stereo usually comes with its own harness and you may want to buy an adapter (from Halfords, Crutchfield or similar) to hook it up to your car harness.
It can be a matter of a few minutes if you know what you are doing, or a few hours plus disassembling the dashboard to get at all the parts.