ABS plastic shrinks as it cools and large objects with thin sections tend to delaminate, as seen in the Barbie Pistol and a few other objects. The box for the GPS+voice interface is four threads thick and 35 mm tall, which provided enough energy to rip the side apart:
Solvent glue and a clamp shoved it back together again:
This one was extruded at 190 °C, which works fine for small objects and isn’t quite enough to fuse something like this. I’ll crank it up to 210 °C for the next iteration to see if that improves the result.