We have two dealers in NJ; one in Sewell and one in Bridgeton. Unfortunately, we do not have information by county. Car Effex is in Sewell, and Lairson Electronics is in Bridgeton.
Installation of our product should not void any warranty. You are not making any significant changes to any factory system that could be blamed for a failure. The Magnuson-Moss Warranty Act states that a dealer must prove that aftermarket equipment caused the need for repairs before it can deny warranty coverage.