Like i said its a safety thing, each car is different and each kit is different, you have to deiced for yourself...like with mine i got a 55w vvme kit, the better the company the better the build quality, or at you would think. 70-100 dollar kits vs 30-50 dollar ones off ebay and you take some risk with build quality, and reliability.. But ive never heard of anyone having a problem with no running a harness.