my single-bulb H4 euro headlites broke when backed into (sniff). So I ask anyone who might know... if I upgrade to the super-cool H4/H1 setup, do I need to change the wiring harness (again)? The one that I have is the Comp. Ltd. one for the single bulb H4. If my existing euro harness won't cut it, is there a way around replacing the whole thing? thanks, -coleman