Old police and emergency communication scanners have gotten pretty cheap. Many of the older ones don't trunk track but can still be used to pick up police and EMT signals, it's just takes a little more listening to follow the conversations. I had an old Bearcat scanner gathering dust on my desk and decided to put it in an old Mustang. The car had an aftermarket stereo installed that opened up a space below the radio that was perfect for the scanner. The scanner did require some custom cutting to fit but came out pretty well.
Thanks for taking a look.