A lightly used UUC Oil Center for sale, pretty much like this one on their website: http://bit.ly/u2Ehda
This piece replaces the cap on your oil filter and gives you two ports to samples your temps and pressure.
Note that this one is tapped for 2 metric-size sensors, so your stock BMW sensors will fit here. Fits these vehicles:
If you're upgrading your motor *at all* you owe it to yourself to add some proper gauges, and this is the easiest way to do so.