I have just about made the decision to drop some $$ and go for one of these:
They are doing a re design to allow the use of the stock cap, so still a few weeks out for ordering.
This looks like the gold standard.....is it?
I do really like the idea of a low water alarm for obvious reasons.
The pinhole in the brand new plastic tank really spooked me. If it was the wife driving, I would be looking at a serious overheat instead of just a new tank! Spendy, but cheap insurance.