Typical HID lights that are equivalent to 55W halogen use approx 4 amps to Run. The problem is that when they start they draw a full 20 amps each for a short period of time (approx 20secs). With 8 lights that you wish to add this will be a draw of 160 amps at once. That sort of load will be an issue fro starting them all at once without fitting a series of relays. My advice would be to get good Auto electrician to wire it up for you with relay for each and maybe a slight delay circuit if he knows how.
Jono
Jono
