I just recently purchased a ford Ranger and had an issue with the arm rest breaking completely off the hinges.... The top was totally broken and removable with minimal effort. I eventually got tired of not having an arm rest. Personally I find it very uncomfortable to drive WITHOUT an armrest.
So I bought two Arm rests that are able to be bolted on, I epoxied the plate and bolted it through the plastic body, (epoxy adds strength instead of relying on the bolts alone).