You will receive a complete installation kit when purchasing this Toyota Celica security alarm for your vehicle so you will have all the necessary components to finish the installation process. Because this Toyota Celica alarm system is OEM you know it will operate correctly and also the installation will be a straight forward process with all connectors matching up so here will be no confusion. You will want this Toyota Celica security system made to factory specifications for your vehicle not an aftermarket system that may not be compatible to your vehicle and could be easily disarmed. No cutting will be required when you purchase this factory Toyota Celica security system for your Celica since it is designed to perfectly fit your specific vehicle because of the correct design.