Well, it turns out that I STILL had a leak at the same place, which was the thermostat cover. It only leaked any amount when I drove it on the highway. I was a bit afraid to try removing the cover bolts because they were very tight in there, but I did manage to get them out, thanks to someone using copper anti-seize on the threads at some point. I just installed a new gasket after cleaning up the aluminum, and a bit of sealant with that gasket for good measure....no more leaks. Yay.
The speakers sound decent, which is good because they were a pain to install. At least they all work.
Seems to be working better than it did last year, especially after a longer drive. It's a heavy truck compared to the Pup, so considering that I guess it does well. Once in a while I'll get a strange look from someone who realizes there is a diesel in there and probably shouldn't be.