If you are looking for something different to add to your diorama Exclusive RC just released a 1/14th scale replica of a Construction DOT Sign Trailer. This trailer comes with a real functional display  that can be programmed with an APP compatible with Android and iOS (Apple) devices.

Main features of the Construction DOT Sign Trailer:

• True Scale 1:14 Construction/ DOT Sign Trailer
• Working leaf spring suspensions made from carbon fiber infused Nylon
• Ball bearings in the wheels
• Real Solid Rubber Tires F
• Functioning tail lights with JST male and female plugs for connections 7-14 Volt friendly (2s-3s) and 2
• 3 mm red leds
• 3 height adjustment for main signboard
• Makeshift solar panels
• Adjustable jack-stands for stability
• Metal hitch
• Charging wire for displays

Source: Exclusive RC