Wiring takes quite a bit of time for remote starts on older cars with no premade harnesses. Then when you add new and old technologies together it takes even more time to make sure it will all work together. I am using an old Code Alarm system with a slightly newer Fortin key bypass unit. After getting the first two main harnesses installed, I inserted a jumper wire across the starter interrupt circuit to make sure it still starts. In case of emergency I can still start run and drive the truck before finishing the install.