I think it's standard operating procedure for some mid to late 90's Cadillacs to put Bars Leaks in following a coolant flush.

I remember reading this for a 98 STS that I almost bought.

The recommendation is to use the powdered Bar's Leaks, not the pellets.

Would I try it? Probably. GM has a specific formula on how much to put in...I think it was two tubes for an STS

I think years ago, this was recommended for Mercedes as well..... quite a few years ago... but don't hold me to it.

My 88 300e is still holding up well under the original head gasket, but I think a lot of that has to do with the previous owners maintainance....althought when I bought it the coolant was green... I flushed that out immediately and put in the yellow stuff.