If you're buring out a relay, there's a reason..... Standard Bosch Relays will handle some 30,000 cycles or some such obnoxious number..... as long as they are not pulling too much current through them. Most are not rated at above 60 amps either. That's a LOT of juice for your headlights, but the right relay, wired correctly, with the correct wire gauge, should last for many years before any issues arise related to the Relay. Most newer cars run some sort of a relay from the factory, to allow less large gauge wire to be used in the vehicle construction. No sense running heavy gauge wire inside, when the battery and the headlights are right there in the same compartment. Just low current wiring to a relay (usually also installed in the fuse block, or its own fuse box), BAM... lower weight cars, lower amp switches in the interior and all.