My turn signal relay is very quiet. It works fine but I would prefer it to be louder so that I am less likely to drive with it on when it does not cancel such as on a wide turn. Are there any louder aftermarket ones out there that would work in a 99?

Now that's a new one. I have never heard anyone say they want a louder switch. I would say my switch from my C1500 is louder than my cavalier. That may require some custom work. Not sure that it would be a plug and play situation and not sure it's a big enough differance to make it with the work. I would say you might benefit from brighter bulbs in the turn signal indicators in the gauge cluster.