I’m helping a friend replace his stereo. The current one is broken and it is loose and flops around. From my experience car stereos usually have a little metal bar/post that sticks out of the back of the stereo and into the mounting bracket to secure it. It is nowhere to be found.
What is this part called so I can order it?
There are probably thousands of different support brackets. Suggest you fabricate. Start by roaming the hardware aisle at Home Depot. You might also stop by a car stereo installation shop. You might get lucky and find someone who’s willing to assist.
Some units have keyhole type slots on the back and sides for the insertion of a stud with a flat spring. A suitably sized bolt may be substituted and locked in place with a nut and washer.
The metal brace that can be (optionally) used to secure the back of the radio to some other part of the car is referred to as a “backstrap” by installers. There may be a more technically correct term for that piece of metal, not sure.
Backstraps used to ship with aftermarket radios, but they don’t come with them anymore.
Some install shops might have a collection of saved backstraps, and they can also order the material from Metra, supplier of installation kits and hardware. You could call a couple of car stereo shops and see if they have an extra backstrap they’ll sell you.
That being said, the backstrap is mostly considered optional, and usually installed to make the radio a little harder to steal. If the radio in this car is flopping around, it’s likely that it’s not installed properly, or maybe it’s sitting in an oversized factory hole instead of being mounted in place with an installation kit.
Couldn’t hurt to visit Metra or Crutchfield to at least get an idea of what the installation kit is supposed to look like.