A few weeks ago
Chad Stett installed his Stage 1 oil cooler on my 135i. In that time it's consistently been running from 195 to 205 degrees. Occasionally in stop and go traffic I've seen higher temperatures, approaching 230, but that's it. No where near the normal running temperature of 235-245 that I've had in the past. I haven't taken it to a track yet, but will next month.
It's located in place of the original cooler and is much larger than the stock one. In addition the piece that attaches to the engine in front of the filter is replaced and braided lines are used. The photos below don't show it real well, but it's the best I can do. Click through the images for larger views on my website.
Prices start at $645, see post #24 for details.
Chad also updated his intake with larger plumbing. He installed the newer version on my car and it does seem to provide a bit more oomph and a little more turbo sound.