I would really like to be able to do this with my car and I dont know how to. Because when I go into the settings, where you hold down info and info reset at the same time, all there is, is lights flash at unlock and a few others but no Horn sound at lock. So basically im wondering if there is any possible way to get that option on my car as I would love to have it, I have a 1997 Eldorado with no Alarm system, which im thinking is why that isn't an option. Thanks Daniel