Fitting this time of item about 10 years ago as part alarm systems or stand alones,along with auto close windows sunroofs etc.
they can be std alone i had one on my ae86 gt corolla and fitted a few for the boys at thew time as a fun/toy/ pose value
also great for winter times just simply get up press button remote start let car run while i had my breaky nice warm car off to work
defrosted and all clear,
had to remember to leave in netural ha ha