courtesy light extender for kia forte

So here is some background. The Kia Forte does not have the Courtesy lights come on or stay on when you unlock or close your car door. I am looking to add this function in an easy to install module. I came across this circuit diagram Original Link and I was wondering, if there is anything you might change or update in this diagram. Would like to add a fade in to this circuit if possible. I am also looking to find a source for all the components, any help would be greatly appreciated.

Although there are some simpler circuits that could be similarly modified with the relays in your diagram - eg: ... your circuit seems ok. Fading in as well as out is a complex circuit. It is usually better done with PICs etc. eg - DigiMotive Dome Light Dimmer