sorry i should've clarified... don't take it off your own car lol... i had a parts car and i took it off that one... or you could just go to a junkyard and snatch it... but its only $3-4 from the dealership anyways.^pretty sure that is there for a reason... it keeps the nasty stuff from the road out of your cabin...
i just went to lowes tonight and bought a rubber ring and a metal hole plug for like 2 dollars.