Had my maxima fixing for coolant leak here. I think he used the 'express leak stop' liquid stuff, didnt solve it. The car ended up overheat. Took it back, he said it has another leak into the engine, then guarantee to "fix" it and charged me for it. Again, didn't solve the problem, coolant still leaking. Now he suspect its waterpump but wont honor his guarantee that the leak would stop and want me to pay for another fix.
In the end I was fed up and went for another mechanic.