fading dome lighting and a relay.

ok, so i hooked up everything this weekend for my car, but i have a slight problem. my dome lights fade on and off when i unlock my car and open the doors. it's not the fading thats the problem, but when it put through the relay the relay really buzzes,b/c it's fading from 0V to 12V and in between it's trying to turn on, but it dosnt fully until 9V.

i assume this is bad for the relay, if not it's still annoying ans all hell. is their something i can do that will make it more like a switch, like a cap or something similar?

the dome lights run off of a negative switch so i have the relay wired with fused power to the pos, and the ground is the dome wire.

if anyone has any ideas it will def help.