[RMVX ACE] FADING ROOF

Basically I have made a gas station for one of my maps and cool that is great but I wanted to have so the roof-y thingy they always have over the gas pumps goes away while the character is under it and reappears when it's not I'm guessing I would go about this using regions and using a picture overlay perhaps? but what is the way you guys think it should be done?
Just two screenshots kinda illustrating what I want (Don't mind the uncolored gas pumps and AMAZING streetlamps)