The water pump is about the only thing I haven't replaced on my 96 Passat. The timing belt, idler and all the seals were not "that" bad. The biggest problem I had was the car spent it's first 10 years in New Jersey and everything metal that had to come off was practically welded together with corrosion. I should have replaced the water pump while I had it all apart, but I didn't . . .

I don't know how different the 99 would be, but if it's like my 96, it's "do-able" IF you have small enough hands, plenty of time and a LOT of patients. By the way, my 96 has the 2.0 ABA engine. If it had the turbo or VR6 engine, I would guess it would have been a lot tougher.