Used car, sudden white exhaust that has sickening smell

if they are a established luxury car dealer , the thought of bad publicity and a letter from your lawyer and a negative report from another shop might do the trick

Supposing the dealer’s service department put some sort of stop leak product in the radiator fluid to sell the car…

and now that I have been there once complaining of white smoke coming out of the tail pipe, supposing they put more stop leak product in…

I read that the stop leak products have the potential of plugging up the heater core, and even reducing the functionality of the radiator.

Is there a test that can be performed on the radiator fluid for the presence of a stop leak product?
(maybe I should start a new thread with just that question)