Guys, I think we are talking about boiling a piece of electronic circuit there. It will be all well-done even before you even take it out for the first testdrive, unless you use military specs, high heat resistance stuff there... I don't know but it will never come cheap.
We are talking about the coolant tank with high temp in the engine bay here, not a washer tank in the trunk.
I don't think I'm willing to pay for a tank that will run closer to $500 with the tendency to crack/ shatter the glass parts when the temp extremely change from one end to the other. BTW that budget will go to few new hood trims from Lotus
The temp gauge might be a little harder to notice than a warning light, but that's what it's for.