I appreciate your post. My wife's VW had the same Walmart R134 done to it and it works great! I was just concerned after reading a couple of posts from 2 guys who said that after they did it their compressor started grinding a while later causing what sounds like a major clean out and new compressor. I am trying to find out if it was coincidence or the result of the change over that caused their compressors to go.It sounds like they did add the ester oil. I would hate to do this retro to my BABY only to have a major disaster later this year or next year. Has anyone had this retro for more than a year with no problems???