No, other than reading about him on here. He has a very good reputation. I remember reading a post about someone with a 500e that had it in and out of shops that could figure the issue out so he took it to Jonathan, which was a very long distance away, and he resolved it. He also likes the cars, which means a lot too. I probably won't get mine upgraded until I get a modded pump. I wound up emailing him and he told me to call. Very informative! He is using a synthetic oil as well. Shoot him and e-mail and see!

__________________
1987 300TDT - 195,000 (Original #14 head)
1993 190E 2.3 - 105,000
1981 300D - 250,000