Jaguar and Subaru are two manufacturers I know of that specifically call for a "stop leak" type of compound to be added to the cooling system as a matter of routine maintenance. That is applicable to certain specific models with known leaking issues right from the factory.
Jaguar of course makes sense, it's English, you know it's gonna leak.
But I was surprised to see Subaru also had some problems in that regard.
I've used the pelletized style Bars Leak for years on many many different cars, works well, never a problem.