I didn't have much to do with the SAZ-4500D no. I just advised against the spring clips, therefore the amp is delayed because they have to make a whole new heatsink and machine it for the screw holes etc for this new amp. Even if I hadn't said anything about the spring clips, as you can see from Jacob's other Sundown Audio amps, he is not fond of them and likely would have done the same thing regardless of my input. Which is a good thing. The factorys sell you those spring clips as the best thing since sliced bread, but that's probably just because it's cheap for them. All of the amp boards that use spring clips could be placed in a regular heatsink with screws and bars, but it would require extra WIDTH of the heatsinks to accomodate it, and that costs more money, and makes the amps larger, which would not allow some people to use them because of mounting issues so they are stuck with spring clip amps.... Most of them make it to right around 1 year without problems from vibration, so the companies that offer the amps don't mind, as their warranty is only 1 year or less, but Sundown's warranty is 2 years.....