There was all kinds of stuff wrong with it in addition to the coolant system problem I was having: tensioner was leaking (or something), timing belt needed replaced, new camshaft and crankshaft seals -- but the guy who did it is a personal friend of my father's, so I'm thinking that it might just be a faulty part or something, which should be covered in the warranty. I don't think he'd rip me off.
Still, he must have not even tested the work he did when the thing is overheating only an hour or so after driving it off the lot.