I bought these as replacements for the original, broken ones...after 20 years! IF you have OEMs installed from the factory, then these plug straight into the factory wiring harness. No modifications required. If you want to add them to a car that came without, they have the harness included in the kit along with a dash switch. I have no complaints and installed them in a brand new bumper cover and now everything looks new. They are as bright as the night driving lights...maybe more. I'd buy again!