Questions about fast glow system on a w123

[MattBelliveau]

I have a few questions. First of all, will it make my car start easier in the winter (less cranking?). Where can I get this car. And can I just change out the relay without changing plugs (without creating a compatability issue). I'd like to wait till it's a bit warmer outsided to change the GPs, as I don't have a garage, and it's been below freezing here for about a week. Thanks guys!