Yeah, we just did a 700 odd Km trip with our caravan, and it was a really good thing we had this setup. We still had some heat issues with the auto, but it would've been a lot worse without this. On the way home I kept the revs under 2600 going up the hills and it didn't get hot.

It's a bit odd at first to have an auto's exhaust burbling when you back off, but the engine braking is good.