I'm surprised that the aluminum u shaped channel even dissipates enough heat This is a heat sink. But it will just absorb heat if the underhood temps are higher than the transistor puts out.
Yes that's a good point too.
If hot heat from headers in engine bay or even just a high perf engine dumping more heat those external heat sinks could bring heat into the modules and make them over heat.
This could be happening right now with even the mopar stock boxes. They could be in a hotter environment than they were designed to run in.
One thing that could be making them fail, or even start missing at high rpms cause they are getting hot ???
Edit: With the heat sinks got to be able to carry the heat away from them, preferably to the outside of the car body.
