Not to thead-jack, but I bought an ER Sport oil cooler, which uses the stock oil thermostat. Took 4 hours at a shop to install. If you don't have the stock cooler and need the "adapter" kit, ER has that available as well. The install is a little easier than the Stett unit. Stett's product is a good one, no doubt, but it all depends on whether you want to bypass the oil thermostat or use their "remotely mounted" unit.
2013 F30 335i M-Sport 8AT/MPE/MPPK, 2016 228i M-Sport Cabrio 8AT