Get yourself a P3 gauge- it's a bit pricey but it displays lots of good information- among them boost, throttle, exhaust gas temperature, air intake temperature, coolant temperature, battery, and 0 to 60 timer. It takes a vent, but also allows the air to come through and looks like it was made for the BMW.
I love mine and I use it especially for the boost numbers and 0-60 times
