enable door handle unlock button?

What I am looking at now is the possibility of using something like the Compustar 2-way system, that has the function to monitor when I get close to the car, and auto unlock the doors. BUT...what I am reading is that the Compustar does not allow this feature in the U.S. Anyone have experience with this on the Compustar, and is it something that can be enabled on all of the 2-way Compustar units by special programming? Would hate to get one of these, *thinking* that it could be setup for this function, only to find out that the U.S. models can't be done. Also, do any of you have experience with any others of the passive "walk-up" keyless entry systems, that will unlock my doors for me? I would like to know of any other types/brands that you may have worked with. Links to the product would be nice, but not necessary. Thanks! Butch

I've messed with quite a few of them and haven't found one that worked decently.  Many of them leaving me standing at the door for a second or two waiting for the doors to unlock which is completely unacceptable (think if it was pooring down rain and you ran to the door just to stand there for 3-5 seconds). 

I have used one system that I really liked and it worked well, but it was meant for engine immobilization on motorcylces and could not be modified to work with door locks unfortunately.

As far as why the manufacturers don't allow you to start the car and then walk away from it is I'm sure there is a safety / liability issue with leaving a car running unattended.  I would be extremely surprised if any manufacturer would be OK with leaving a car 100% unattended let alone encourage the owner to do so by allowing what you are asking for.  At least remote start systems incorporate tach checking (to prevent damage) and safety shutdowns (to prevent theft). 

Kevin Pierson

In fact Kevin, legally they are still a grey area in the UK. Think of one shot windows, up or down in Japan or Europe, PT cruiser, down only. Rolls Royce and GM cars (at least in the 60s) had the power windows always working. Nowadays ignition control only.