The system is only "live" when the ignition is on (it is where I've wired it to the feed for the rear light) so no probs on the battery front.
When you ring Autocom, mention you saw good feedback from people on this site, you never know, we could build up a discount for future member purchases
Oh, don't be a male chauvinist like me

and assume the girl who answers is "just" a receptionist, she is VERY knowledgeable on the products