perfectly good 3.5mm jack
You say perfectly good, I say horrible. I use a Bluetooth adapter (under $7 on Amazon, one of the best electronics devices I've ever bought) in my car.. It uses a wire with 3.5mm connections on both ends in between the main electronics chunk that plugs into the USB port in the car (so it has no batteries to charge).. The headphone jack connections get flaky, so I have to wiggle/twist them.
It's not unique to this device either, it's definitely happened to my iPod & iPhone connections over the years (and I'm almost positive Walkman-like devices before that).
BTW, I'm not saying you have to buy expensive headphones either. I have what are to me perfectly usable Bluetooth headphones that were $20. (I also had previously bought ones that _looked_ like the old iPhone earbuds with just a wire between them, and 2 of them broke within weeks.. they were crap)