When I had my Prelude and Passport, the intervals were at 60K...the Prelude had 30K when sold so I never got that one replaced.
Neither had cooling system problems during my ownership.
Had my W124 water pump fail at around 97K. Water pumps have a "weep hole" that when the seals go, coolant starts dripping out of the hole. Mine just dumped coolant all over the floor when it went!
This was in the days before I joined the forum (although I'm not sure I would tackle that job anyway), and I was out $750 at the dealer for the R&R.