Code 3 Sirens:
Add more terminals to the rear for us to use. It's insanely difficult to connect 6 or 7 activation wires to the Slide Switch 3 Terminal on a V-Con or MasterCom (3892L6) control head because of a lack of serial control of any kind. There's just not enough room. Also, PLEASE relocate your dip switches that adjust settings such as LightAlert and Park/Kill to the back of the unit, with a hole in the cover, so we can change those without having to take off the entire housing. This is the biggest pain in my ass I've had as an installer dealing with existing installs on these units.
And PLEASE make the 8-gauge wire come with a connector that pops in and out of the back of the unit. Whelen does this for every siren unit they have, as do several other manufacturers. Why can't you? It really gets expensive to have to put a new super-big butt-splice on this wire every time I need to take it out of the vehicle for changes or service.
Speaking of connectors, I would suggest just ditching the screw-down connector terminals altogether. It's very frustrating having wiring coming out of the respective holes when you can't secure them to a terminal or connector with a crimped connection. Sure, it's nice saving on terminals and the ability to quickly remove them, but I'd rather tear apart a console or wiring board for a bad crimp than for a wire that vibrated loose out of the screw terminals (either that or redesign the concept so it holds more securely).