Thanks, guys, for the helpful answers to my query.
It was VERY helpful to know that the red light meant low coolant.
Turns out it was a slow leak ... which turned into a large leak
the next day. Scheduled a visit to the dealership and drove carefully
the two miles down there with an almost dry engine !!

Service department confirmed a split plastic coolant pipe; they have
a spare in stock for about $140 ... but there's 4 hours of labor to
remove-reinstall the fuel tank to replace the pipe. So I ask, should
I replace the other pipe next to it while we are at it ?

Service advisor says no, they are supposed to last a life time, and
the other one looks fine. Service manager says it makes sense to do
both, but they don't have the other one in stock, so I'd be bus-less
at least until Tuesday. So I told him to fix what he can with the part
he has.

Am I likely to regret that ? Should I call him up in the morning and
say "hold it" ?

(Was I too naive to think that if I pay $15K for a bus, it will be usable
for the daily drive to work ?)

/ Lars