A great simple solution. My factory plastic plug was almost completely rusted on my 2006 325i with 174,000 miles. The o-ring in this kit provides a very tight fit to the body. I tried a couple of times to get it all the way in and I lubricated the o-ring but it still didn't work so I just screwed it in but it doesn't leak so I guess it's ok. I needed to get my car repaired quickly and that helped.