My ZT had a standard plastic housing and not had a problem with it in 6 years and 60k miles.
It was changed at the same time as the cam belts last year but there was not anyting wrong with it no leaks nothing just made sense while everything was exposed to pop in a new one.
Is the problem with the plastic themostat housing actually that bad? In my experience the plastic housing is servicable for as long as one would expect it to be.
Maybe the constant hot weather in South Africa degrades it quicker?
Ed.
