... Never park it with anything inside that you cannot afford to lose!
I learned this lesson long ago when someone broke out a window and stole my (expensive to me then) stereo. Ok lesson learned. A vehicle is not secure, no matter what. Never leave anything in a parked car that I can't afford to lose. If someone want's it bad enough they'll pick it up with a fork lift and take it away on a semi trailer.
Fast forward to today... driving a rag-top. That means anyone with a knife has "a key" to the car. And if I lock the door, "forcing" the thief to use the knife to get access to the lock, it's my fault* for locking the door."
Fortunately the march of progress has meant car stereos are almost free. The last one was $40, delivered. I can afford to write off $40, just please don't cut the top! That also has nearly eliminated the profit in stealing car stereos.
Many years later, that $40 radio seems to have developed a fault, I'm guessing in the amplifier section. Probably an occupational hazard when most of the time it's being driven at 100% (the scale goes to 42)... These are the hazards of trying to listen to the radio with the top down at 70mph.
FF to today... The SCSon announced "nothing interesting the Fry's ad today". "What about a car stereo?" I asked...
I can do $15. lemme see. SD card... aux input... It's almost perfect. Also lamenting the $DayJob can't sell an empty cardboard box for that price. OK, different problem, but still... Shudder!
But you know what I don't get for $15? AM reception! The next least expensive model with AM was nearly 4x at $55. But you know what? I have several AM handheld radios and an aux cable..
It's also educational to understand the reason why FM is now easy and AM is hard (when it used to be the other way around). It's because radios are now mostly digital while they used to be analog. Analog AM radio was easy-peasy - diode detector stuff + amplifier while FM was harder. Now it's digital, SDR (Software Defined Radio). Plug an antenna to one end of the chip... chip converts RF via an Analog to digital converter... detects the encoding... reconverts to audio and a speaker connects on the other side. I'm guessing the lower frequencies of AM make it harder? (I don't actually know).
* I'm going to credit this thought to Ms. Tam, rather than claim it an original thought or research the actual link.