The heat ex is the first I've heard of being as regular equipment on a MB diesel. I had to add one to mine but it was for the WVO. I bet it would be easy to bypass the thermostat and to make it run all the time for the WVO.
My car smells more like a grease burning on a BBQ going down the road or while idling.
Feels good to thumb my nose at gas stations as I pass them.
