I had my '99 E300TD reprogrammed at Speedtuning 2 weeks ago. Got the K&N as well. Its transformed the car. Had my Mercedes mechanic drive it -he was going to take it around the block -a couple of miles later he was stilling exclaiming wow! this really feels like a lot more power.

Needless to say I'm happy. The car has 130,000 miles on it. Right before I had it chiped it got a complete overhaul. New nozzles, tie rods, AMG springs, Bilstein sport shocks, H+R sway bars, new bushings, etc. As soon as I put in the Magnaflow turbo-back dual exhaust I'll be ready for the next 130,000 miles.