I have that exact leak on my TD. I looked underneath and there is tranny fluid leaking from one of the cooler lines. I haven't had a chance to look into further. Actually when I changed the fluid and filter, I accidental put a "tad" too much tranny fluid (Mobil 1) in. SO it leaking a bit is actually helping me get rid of the excess. Of course I can't let it go on leaking. Any ideas on what these lines cost?

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member