RC Crawlers are amazing fun to play with and to add more realism, you can always pull trailers and other RC Vehicles or loads on trailers.
This is my own designed 3D Printed RC Trailer that does a great job. It has ramps to let the RC Vehicles climb up and down and you can store the ramps under the trailer. You do need to use some foam to lock them up in place. so the do not fall off.
There are a couple of STL Files due to complexity of trailer, so print them all and then use glue to join them. Works like a charm and looks great.
20% infill settings or as per your choice to make it stronger
Printed on Creality3D CR10S at speed of 200%
use supports when needed
use rafts for Axle or where needed